RESEARCHES  IN  STELLAR  PHOTOMETRY 


DURING  THE  YEARS   1894  TO   190(5 


MADE   CHIEFLY    AT   THE 


YERKES    OBSERVATORY 


BY 


JOHN  A.  PARKHURST,  S.  ML, 


Instructor  in  Practical  Astronomy  in  the  University  of  Chicago. 


WASHINGTON,  D.  C. : 

Published  by  the  Carnegie  Institution  of  Washington 
October,   1906 


RESEARCHES  IN  STELLAR  PHOTOMETRY 


DURING   THE  YEARS    1894   TO   1906 


MADE  CHIEFLY    AT   THE 


YERKES    OBSERVATORY 


BY 


JOHN  A.  PARKHURST,  S.  M., 

Instructor  in  Practical  Astronomy  in  the  University  of  Chicago. 


WASHINGTON,  D.  C. : 

Published  by  the  Carnegie  Institution  of  Washington 
October,   1906 


^ 


Attron.  Deft, 


CARNEGIE  INSTITUTION  OF  WASHINGTON. 
PUBLICATION  No.  )}. 


DEFT  i*- 


PRESS  OF  GIBSON  BROS., 
WASHINGTON,  D.  C. 


CONTENTS. 


PAGB 

Introduction,  Plan  of  work,           . i 

Chapter    i. — Instruments 5 

Chapter    2. — 103  T  Andromedae, 1 1 

Chapter    3. — 267  V  Andromedae, 31 

Chapter    4. — 787  W  Andromedae, 45 

Chapter    5. — 4315  R  Comas, 59 

Chapter    6. — 5798  RU  Herculis, 73 

Chapter    7. — 6100  RV  Herculis 87 

Chapter    8. — 6894  S  Lyrae, 103 

Chapter    9. — 7220  S  Cygni, 117 

Chapter  10. — 7269  SX  Cygni, 133 

Chapter  u. — 7458  V  Delphini 145 

Chapter  12. — 8518  Z  Cassiopeiae, 161 

Chapter  13. — 8629  Y  Cassiopeiae, 175 

Chapter  14. — General  Conclusions,  Precision  of  Measures,  Limit  of  Vision,     .        .  187 


960569 


INDEX  TO  TABLES  AND  FIGURES. 


TABLES. 

List  of  Variable  Stars table      i,  page 

Summary  of  Visual  Observations 

Absorption  of  Photometer  Wedges 

Limit  of  Vision  of  Telescopes J 


Agreement  of  Magnitude  Results  for  Standard  Stars 
"  "  "         "    Measured    " 


2, 
3, 
4, 

"9, 
"7, 
118, 


4 

10 

10 

190 

1 88 

189 


omedae. 

to 
•o 
u 

romedae. 

to 

VI 

\ 

en 

3 

fij 

B 
M 

'H 
'£ 

K 
'C 
o. 
_o 

iopeiap. 

M 

•o 
c 

1 

•o 

E 
o 

X 

W 

8 

X 

X 

o 

S 

rt 

a 

«! 

•3 

^ 

0 

p 

> 

>4 

O 

X 

M 

6 

o 

H 

> 

* 

rt 

rt 

P) 

03 

w 

w 

> 

N 

_** 

Standard  Magnitude  Stars.  -J  ~g^ 

5 
ii 

15 
32 

24 
46 

33 
59 

43 
73 

52 
87 

61 
103 

70 
117 

80 

89 
146 

99 
161 

108 

175 

Comparison  Stars  in  B.  D.  (table 

6 

16 

25 

34 

44 

53 

62 

71 

81 

90 

IOO 

109 

Catalogue  ^  page 

12 

""2 

46 

60 

74 

87 

1  04 

117 

I  -37 

146 

161 

176 

Notation,    Positions,   and  (table 

7 

17 

T1 

26 

35 

/  T^ 

45 

/ 

54 

»  Vf 

63 

72 

*  OO 

82 

*  1™* 
91 

IOI 

no 

Magnitudes  of  Compar-  •< 

ison  Stars             .             (page 

I  2 

•32 

4.7 

60 

74 

88 

IO4 

118 

I  "^4 

147 

162 

176 

Photometer    Measures    of  J  table 

8 

O"* 

18 

27 

36 

/  *T 

46 

55 

64 

73 

83 

92 

102 

*  /  v 
III 

Comparison  Stars     ....   i  page 

I  "I 

•JA 

60 

88 

118 

148 

162 

177 

Constants    for   Reduction  (table 

1  3 

9 

Of 

19 

28 

37 

47 

56 

65 

74 

84 

l£f.VJ 

93 

*  /  / 
112 

and     Comparison    with  -.' 

Catalogue  Magnitudes.  .  (page 

'7 

37 

51 

64 

78 

92 

1  08 

122 

138 

15' 

1  66 

1  80 

Mean  Magnitudes  of  Com-  (table 

IO 

20 

29 

38 

48 

57 

66 

75 

85 

94 

104 

"3 

parison  Stars  "<  page 

18 

-,8 

7O 

Q-l 

IOO 

124 

152 

168 

181 

Visual  Observations  of  the  (table 

ii 

3^ 
21 

30 

39 

/  y 
49 

:7J 

58 

67 

*      T^ 
76 

86 

95 

105 

114 

Variable                               *  page 

20 

«Q 

66 

81 

QC 

I  IO 

I  J.O 

T  C  7 

T  60 

182 

Mean    Magnitudes  of  the  (table 
Variable  from  Grouped  < 

12 

22 

31 

40 

50 

yo 

59 

68 

77 

!*(.!_• 

87 

A  OO 

96 

**ry 

106 

"5 

Observations  (page 

26 

42 

s6 

7O 

8s 

IOO 

114 

129 

143 

157 

172 

185 

Observed      Maxima     and  f  table 

13 

T" 

23 

32 

/ 
41 

J 

51 

60 

78 

88 

98 

107 

116 

Minima  \  page 

27 

^6 

71 

86 

1  02 

116 

I  IO 

144 

1  60 

173 

jg  r 

Measures  by  other  Obser-  (table 

*  / 

/  * 

42 

3 

79 

4  *T*T 

97 

vers  1  page 

28 

71 

I  ^O 

I  QQ 

/  * 

*  o 

*  Jy 

FIGURES. 

Photographic  Chart  opposite  page 

12 

32 

47 

60 

74 

88 

104 

118 

134 

I 
147 

162 

176 

Magnitude-Curve  .                 J    %' 

4 
24 

7 
33 

IO 

13 
64 

16 

80 

'9 
94 

22 
1  08 

25 

123 

28 
"38 

31 

IS' 

34 
167 

37 
1  80 

(page 

Light-Curve  .                        -<fig" 

5 
25 

8 

43 

1  1 

55 

'4 
69 

17 
84 

20 

99 

23 

"3 

26 

128 

29 
142 

32 
156 

35 
171 

38 
184 

'   (page 

Mean  Light  -Curve.  ..        ..  J***' 

6 

27 

9 

44 

12 

57 

15 

72 

18 
86 

21 
IOI 

24 

"5 

27 
130 

30 
143 

33 
158 

36 
172 

39 
1  86 

(  page 

RESEARCHES  IN  STELLAR  PHOTOMETRY. 


BY  JOHN  A.  PARKHURST. 


INTRODUCTION. 

The  problems  of  stellar  photometry  are  closely  connected  with  many  cosmic 
questions,  primarily  with  the  light  changes  of  variable  stars;  but  they  have  an 
equally  important  bearing  on  the  questions  of  stellar  distribution  and  evolution. 
It  has  been  said  by  good  authorities  that  it  is  of  more  importance  to  measure 
the  light  than  the  place  of  a  star,  and  if  one  considers  merely  the  astonishing 
number  of  variable  stars  now  being  discovered,  it  will  be  admitted  that  the  import- 
ance of  stellar  photometry  can  scarcely  be  overestimated.  The  material  here 
submitted  is  the  natural  outgrowth  of  the  writer's  variable-star  work,  the  plans 
being  extended  as  the  instrumental  and  other  facilities  were  improved. 

The  following  contribution  is  offered  towards  the  solution  of  several  pho- 
tometric problems,  among  them  being: 

(1)  The  accurate  determination  of  complete  light-curves  of  twelve  variable 
stars  of  long  period,  having  faint  minima. 

(2)  The  question  of  the  behavior  of  variable  stars  during  their  faint  stages 
which  can  only  be  observed  with  the  largest  apertures. 

(3)  The  adaptation  of  the  Pickering  "equalizing  wedge  photometer"  to  the 
determinations  of  magnitudes. 

(4)  The   photometric    measurement   of   very  faint    magnitudes,   and   their 
relation  to  estimates  founded  on  the  limit  of  visibility  of  different  apertures  of 
telescopes. 

I  wish  to  acknowledge  here  the  efficient  assistance  rendered  in  the  reductions 
by  Miss  Kate  Bloodgood,  also  by  Mr.  F.  R.  Sullivan  of  the  observatory  staff,  who 
recorded  all  the  photometric  measures  made  with  the  4o-inch  telescope. 

HISTORICAL. 

The  writer's  variable-star  work  began  at  Marengo,  Illinois,  in  May,  1893,  with 
visual  comparisons  by  Argelander's  method  of  a  list  of  long-period  variables, 
including  at  first  the  circumpolar  stars  in  Professor  E.  C.  Pickering's  pamphlet, 
"Variable  Stars  of  Long  Period, "  published  in  1891;  with  additions,  from  time 
to  time,  of  new  variables  which  were  not  receiving  sufficient  attention  elsewhere. 
By  the  end  of  1899  the  number  of  observations  amounted  to  about  5,000,  fur- 
nishing data  for  determining  162  maxima  and  n6  minima.  Provisional  results 
were  published  in  the  Astronomical  Journal,  vols.  13  to  21,  and  in  Popular  Astron- 
omy, vols.  2  to  8.  This  work  was  made  possible  largely  by  the  kind  assistance 
of  P.  S.  Yendell,  of  Dorchester,  Massachusetts,  who  with  great  patience  gave  the 
instructions  needed  by  a  beginner  and  corrected  the  errors  into  which  one  was 
so  likely  to  fall;  also  of  Henry  M.  Parkhurst,  of  Brooklyn,  New  York,  who,  beside 


2  RESEARCHES   IN   STELLAR   PHOTOMETRY. 

other  assistance,  made  photographic  copies  of  the  forty  Durchmusterung  charts, 
then  out  of  print,  making  possible  the  finding  of  the  newer  variables  and  the  iden- 
\tiric:8Jtj6n;  of  the  brighter  comparison  stars;   and  of  Prof.   E.  C.  Pickering,  who 
furnished  "charts  and  photometric  magnitudes  of  many  of  the  comparison  stars. 
1  J«0  "'•'•  'The  instrument  used  so  far  was  a  6. 5-inch  reflector  by  Brashear,  but  connection 
with  the  Yerkes  Observatory  for  three  months  in  1898  and  since  January,  1900, 
has  made  possible  the  extension  of  the  work  to  the  determination  of  the  minima 
of  very  faint  stars,  fixing  the  photometric  magnitudes  of  the  stars  used  for  com- 
parison, and  making  photographic  charts  of  the  fields  surrounding  the  variables. 

PLAN   OF   WORK. 

Two  points  were  determined  from  the  start :  ( i )  To  follow  the  variables  as  far 
as  possible  throughout  their  period;  (2)  to  give  special  attention  to  the  positions 
and  identifications  of  the  comparison  stars.  To  carry  out  the  first  point,  prefer- 
ence was  given  to  circumpolar  stars,  which  could  be  followed  the  year  around. 
To  fulfill  point  2,  the  coordinates  of  the  comparison  stars  from  the  variable 
were  measured  with  a  filar  position  micrometer,  at  first  on  the  6-inch,  afterwards 
for  twenty  fields  with  the  4o-inch  for  the  faint  stars.  The  completion  of  the 
24-inch  reflector  in  1901  made  it  possible  to  accomplish  this  object  much  easier 
and  better  by  photography,  so  beginning  in  November  of  that  year  plates  were 
taken  to  show  the  faintest  comparison  stars  used. 

The  addition  of  the  Pickering  equalizing  wedge  photometer  to  the  outfit  in 
1900  made  it  possible  to  complete  the  plan  of  work  by  adding  (3)  the  determina- 
tion of  the  photometric  magnitudes  of  the  comparison  stars,  based  on  standard 
stars  which  had  been  measured  both  at  Harvard  and  Potsdam.  The  publication 
of  the  Harvard  catalogue  and  the  approaching  completion  of  the  Potsdam  work, 
including  all  stars  north  of  the  equator  to  magnitude  7.5,  furnished  the  basis 
for  this  work,  but  it  did  more  than  that;  it  called  for  a  minute  comparison  of 
the  two  magnitude  systems  in  conditions  of  practical  work.  It  is  not  enough 
to  know  the  average  differences  between  the  two  systems;  the  practical  question 
is,  What  systematic  differences  will  be  found  in  standards  selected  for  a  particular 
field?  To  anticipate  the  results  discussed  in  Chapter  XIV  it  may  be  stated  here 
that  the  irregularities  found  in  the  systematic  differences  leave  an  outstanding 
uncertainty  of  about  o.i  magnitude  in  stars  as  bright  as  7.0. 

ESSENTIALS  FOR   GOOD  VISUAL   COMPARISONS. 

Among  the  precautions  kept  in  mind  to  insure  good  visual  comparisons, 
the  following  were  foremost : 

(1)  The  two  stars  to  be  compared   were  made  parallel  to  the  line  of  the 
eyes.     To  the  writer  this  precaution  was  of   the  utmost  importance,  for  if  two 
equal  stars  were  placed  in  a  vertical  line  the  lower  would  appear  more  than  half 
a  magnitude  the  brighter.     The  required  position  of  the  stars  was  easily  secured 
with  the  6-inch  reflector  by  turning  the  tube  in  its  cradle. 

(2)  Two  or  three  comparison  stars  were  used  at  each  observation  if  they 
could  be  found  in  proper  distances  and  magnitudes,  though  this  rule  often  con- 
flicted with  the  two  following. 


INTRODUCTION.  3 

(3)  The  stars  to  be  compared  should  be  in  the  same  field,  and 

(4)  The  interval  in  brightness  should  be  less  than  half  a  magnitude.     If  this 
limit  was  exceeded  the  comparisons  were  weighted  in  the  reductions,  inversely 
as  the  interval. 

(5)  Prejudice  which  would  arise  from  anticipating  the  star's  expected  changes, 
was  avoided  by  postponing  the  reductions  till  the  maximum  or  minimum  was 
completed.     The  observing  list  was  long  enough  so  that  the  previous  observa- 
tions were  usually  forgotten  at  the  time  of  a  comparison. 

(6)  The  comparison  of  too  bright  stars  was  avoided  by   reducing  the  aper- 
ture when  necessary. 

(7)  Light  in  the  eyes  was  avoided  by  using  for  recording  a  one-candlepower 
incandescent  lamp,  so  shielded  as  to  illuminate  faintly  a  circle  one  or  two  inches 
in  diameter  on  the  record  book. 

ESSENTIALS   FOR   GOOD   PHOTOMETER   MEASURES. 

Experience  taught  the  necessity  of  close  adherence  to  the  following  principles : 

(1)  A  sky  free  from  clouds  and  of  uniform  transparency  is  the  prime  requisite. 
A  "patchy"  sky  is  a  signal  to  stop  photometric  work.     All  observers  agree  to 
this  in  theory,  but  their  adherence  to  it  is  a  variable  quantity,  yet  it  is  doubtless 
the  largest  single  factor  affecting  the  quality  of  the  work.     According  to   my 
experience  a  lack  of  transparency  amounting  to  a  perceptible  haziness  is  liable 
to  introduce  a  systematic  error  in  the  night's  measures.     This  is  not  the  "local" 
error  entering  when  distant  regions,  like  polar  and  equatorial,  are  compared; 
but  it  shows  in  measures  of  a  field  limited  to  one  degree  in  diameter. 

(2)  Measures  of  a  field  should  be  repeated  immediately,  in  inverse  order  from 
the  first  set,  to  eliminate  progressive  changes  (a)  in  the  transparency  of  the  air 
and  (6)  in  the  brightness  of  the  artificial  star.     Under  (a),  at  least  in  the  climate 
of  the  northern  Middle  States,  progressive  change  in  the  transparency  of  the  air 
is  to  be  expected  from  hour  to  hour,  and  I  suspect  that  this  is  true  in  all  except 
a  few  favored  regions.     Admitting  this,  the  duty  of  repetition  in  inverse  order 
follows.     The  neglect  of  this  apparently  obvious  precaution  in  most  photometric 
work  is  difficult  to  explain  or  justify. 

(3)  The  real  and  artificial  stars  should  resemble  each  other  closely.     This  was 
possible  in  the  present  work  with  the  6-  and  1 2-inch  telescopes,  the  stars  being 
usually  indistinguishable,  but  it  was  not  always  possible  with  the  4O-inch. 

(4)  The  stars  to  be  compared  should  be  in  a  uniform  relative  position.     The 
practice  of  the  writer  has  been  to  place  them  in  a  horizontal  line,  with  the  real  star 
to  the  left  of  the  artificial,  and  distant  about  0.4  the  space  between  the  two  images 
of  the  artificial  star.     Following  the  principle  mentioned  under  (i)  in  "Visual 
comparisons ' '  this  uniform  position  seemed  preferable  to  the  four  recommended 
by  Professor  Ceraski. 

(5)  Nothing  but  the  photometer  lamp  should  be  in  the  circuit  from  the  storage 
cell  supplying  the  current,  and  there  should  be  no  sliding  contacts  in  the  circuit; 
all  should  be  soldered  or  screwed.     The  lamp  should  burn  very  nearly  at  its 
specified  candlepower. 


RESEARCHES  IN  STELLAR  PHOTOMETRY. 


(6)  At  least  three  standard  stars  should  be  used  in  each  series;  the  measures 
of  a  field  should   be   made  on   at   least  three  nights;  three  settings  of  the  pho- 
tometer on  each  star  (repeated  as  specified  under  (2),  making  six  settings  in  all). 
Experience  convinced  the  writer  that  three  settings  were  as  good  as  four,  with 
the  added  advantage  that  three  could  be  kept   in  mind  and  recorded  at  once. 

(7)  The  use  of  too  dark  a  shade  glass  (see  Chapter  I)  should  be  avoided,  a 
change  as  great  as  two  magnitudes  in  the  background  had  an  injurious   effect 
on  the  measures. 

Table  i  gives  the  selected  list  of  variable  stars  in  whose  fields  the  investi- 
gations were  conducted,  with  a  summary  from  the  following  chapters  of  the  periods 
determined  and  the  magnitudes  at  maxima  and  minima.  The  positions  given 
were  (with  the  single  exception  of  RU  Herculis)  measured  with  the  filar  microm- 
eters on  the  6-  and  4O-inch  telescopes. 

Table  2  summarizes  the  visual  observations  of  the  variables,  giving  the  num- 
ber, limiting  dates,  and  resulting  number  of  maxima  and  minima. 

TABLB  i. — LIST  OF  VARIABLE  STARS. 


Star. 

1900. 

Period. 

M--m. 

Range. 

RightAscension. 

Declination. 

Max. 

Min. 

103      T  Andromedae  

km      s 
o  17  10.0 
o  44  39-7 

2    II    14.  I 

ii   59     8.4 
16     6     2.7 
16  56  44.7 
19     9     6.3 

20     3  24.7 

20    II    33.2 

20  43  13.6 
23  39  39-9 
23  58  13-8 

919 

+  26    26    27 

+  35     6  30 
+  43  50  26 
+  19  20  19 

+  25  19  56 
+  31   22   18 
+  25  50  17 
+  57  41   52 
+  3°  45  58 
+  18  58     i 
+  56     i  33 
+  55     7  25 

d 
284 
259 
396 
361.8 
484 

200 
438 
326 
409 
529 
492 
4IO 

d 
126 
in 
192 
119 
217 
81 

'54 
162 

173 
161 

'73 
158 

Mag. 

8-5 
9.0 

7-5 
8-5 
7-5 
9-7 

IO.O 
IO.O 

9.0 

8 

IO.2 

9-i 

Mag. 
13.0 
14.0 
13-8 
14.0 
14.0 

15-3 
15.0 
16.7 
14.0 
17 
15-2 
14.0 

267      V  Andromeda  
787     W  Andromedae  

5798  RU  Herculis     

6100  RV  Herculis  

7220      S  Cygni  

7269  SX  Cygni 

7458      V  Delphini 

8518      Z  Cassiopeia     .  .  .  . 
8629     Y  Cassiopeiae  

TABLE  2. — SUMMARY  OF  VISUAL  OBSERVATIONS  OP  THE  VARIABLES. 


Star. 

Number 
of   obser- 
vations. 

Began  — 

Ended  — 

Number  of  — 

Max. 

Min. 

103      T  Andromedae  

173 
109 

75 
132 
136 

55 
no 

100 

75 
140 

IOO 
IOO 

1894  Mar. 
1897  Jan. 
1899  Feb. 
1894  Mar. 
1897  Jan. 
1897  Aug. 
1896  Oct. 
1892   Dec. 
1899  Oct. 
1894  June 
1898  Nov. 
1898  Feb. 

1905  Nov. 
1905  Dec. 
1905  Dec. 
1905  Aug. 
1905  Oct. 
1905  Nov. 
1905  Nov. 
1905  Dec. 
1905  Nov. 
1905  Dec. 
1905  Nov. 
1905  Nov. 

ii 
10 
6 

8 
6 

H 

8 

9 

5 
7 
4 

7 

12 
IO 

6 
IO 

6 

13 
6 
8 

5 
6 

4 
7 

267      V  Andromedae 

787     W  Andromeda  .  . 

4315     R  Comae  

5798  RU  Herculis    .  ..   . 

6100  RV   Herculis  

6894       S  Lyrae 

7220      S  Cygni  

7269  SX  Cygni   .  . 

7458      V  Delphini  

8518      Z  Cassiopeiae  

8629     Y  Cassiopeiae  .  . 

Total  

1,405 

95 

93 

STELLAR    PHOTOMETRY. 


PLATE    1 


EQUALIZING  WEDGE  PHOTOMETER  ON  4O-iNcn  TELESCOPE. 


CHAPTER  I. 

INSTRUMENTS. 

The  visual  and  photometric  work  was  done  with  three  different  telescopes, 
of  6,  12  and  40  inches  aperture,  thus  making  it  possible  to  follow  the  variable 
stars  throughout  their  cycles,  and  to  measure  the  magnitudes  of  all  the  comparison 
stars  needed.  The  lack  of  homogeneity  in  the  visual  comparisons,  resulting  from 
the  use  of  such  different  apertures,  could  not  be  avoided,  but  its  harmful  effect 
was  kept  within  limits  by  the  use  of  the  photometric  magnitudes  of  the  com- 
parison stars. 

The  6-inch  reflecting  telescope,  made  by  Brashear,  is  provided  with  driving 
clock,  circles  (the  hour  circle  movable),  and  rotating  tube,  making  zenith  observa- 
tions comfortable,  also  making  it  possible  to  bring  the  line  of  the  two  stars  com- 
pared parallel  with  the  line  of  the  eyes,  a  matter  of  prime  importance  in  visual 
work.  Standard  stars  from  the  Harvard  and  Potsdam  catalogues,  chosen  between 
the  6th  and  8th  magnitudes,  could  be  matched  in  brightness  by  the  artificial 
star  of  the  photometer.  If  brighter  than  the  yth  magnitude  the  shade  glass  was 
used,  its  cell  being  hinged  so  that  it  could  be  turned  into  the  cone  of  rays  between 
the  ocular  and  the  flat.  The  visual  limit  of  the  6-inch  with  a  power  of  150  is 
about  13.0  (see  p.  10),  but  with  the  power  of  40  used  with  the  photometer  it  was 
not  possible  to  make  accurate  measures  of  stars  fainter  than  i  i.o,  while  in  practice 
the  stars  measured  were  between  8  and  10. 

The  i2-inch  Brashear  refractor  and  the  4o-inch  Clark  refractor  of  the  Yerkes 
Observatory  need  no  special  description.  Their  visual  limits  are  about  14.5  and 
17.0  magnitude,  respectively.  In  the  photometric  work  the  greatest  accuracy  is 
secured  by  connecting  with  the  1 2-inch,  standards  between  8th  and  gth  magnitude 
with  measured  stars  of  about  the  i2th  magnitude,  then  with  the  4O-inch  to  pass 
from  the  i2th  magnitude  to  the  faintest  stars  possible,  about  the  i6th  magnitude. 

THE  EQUALIZING  WEDGE  PHOTOMETER  AND  THE  DETERMINATION  OF  THE 
ABSORPTION  OF  ITS  WEDGE. 

In  pursuance  of  a  plan  for  cooperation  in  determining  standards  for  faint 
stellar  magnitude,  Prof.  E.  C.  Pickering  sent  to  the  Yerkes  Observatory  in  April, 
1900,  one  of  the  five  wedge  photometers  which  he  had  devised  for  the  work.  This 
was  to  be  used  with  the  4O-inch  refractor  in  the  measurement  of  the  faintest  stars 
included  in  the  plan.  The  construction  of  the  instrument  is  shown  in  fig.  i  and 
Plate  i.  The  tube  T,  carrying  the  ocular  O,  slides  into  the  tailpiece  of  the 
telescope.  At  right  angles  to  this  is  the  tube  C,  carrying  the  essential  parts  of 
the  photometer.  The  light  from  a  one-candlepower  incandescent  lamp  L  shines 
through  a  minute  hole  in  the  diaphragm  D  upon  a  piece  of  ground  glass  G,  forming 

5 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


an  artificial  star.  In  contact  with  G  is  a  piece  of  blue  glass  to  render  the  light 
of  the  star  less  yellow.  An  image  of  this  star  is  thrown  by  the  projecting  lens 
P  upon  a  plate  of  plane-parallel  glass  B  and  reflected 
from  both  surfaces  into  the  focus  of  the  ocular  0,  forming 
at  E  and  F  two  images  of  the  artificial  star.  Interposed 
in  the  path  of  these  rays  is  the  photographic  wedge  W, 
movable  at  right  angles  to  C  by  the  rack  and  pinion  R . 
The  short  tube  carrying  the  ground  glass  G  is  movable  away 
from  the  diaphragm  D  by  means  of  the  head  of  the  screwS, 
projecting  through  an  inclined  slot  in  the  farther  side  of 
the  tube  C.  By  this  means  the  artificial  star  can  be  made 
larger  and  less  sharply  defined ,  thus  resembling  more  closely  a 
real  star  under  different  atmospheric  conditions.  Finally, 
a  pair  of  shade  glasses  at  A  can  be  moved,  either  both  or 
singly,  into  the  path  of  the  rays. 

In  photometers  made  on  this  principle  the  all-important 
condition  to  be  fulfilled  is  that  the  images  of  the  real  and 
artificial  stars  should  closely  resemble  each  other.  The 
range  of  adjustment  of  the  ground  glass  G  was  found  to  be 
insufficient  to  meet  this  condition  with  the  different  tele- 
scopes on  which  the  photometer  was  to  be  used ;  therefore 
the  diaphragm  D,  originally  provided,  which  had  a  single 
aperture  0.17  mm.  in  diameter  was  replaced  with  a  movable 

d  iaphragm 
carrying  four 
apertures , 
o.  i  o,  0.15, 
o.  2  o,  and 
0.25  mm.  in 
diameter.  By 
choosing  the 
most  suitable 
aperture  and 
c  ombining 
with  it  a  slight 
movement  of 
the  ground 
glass,  it  was 
possible  to 
give  the  disk 
of  the  artifi- 


Scale  -  in  thes 
FIG.  i.— SECTION  OF  PHOTOMETER. 


cial  star  any  required  size  and  sharpness  to  suit  the  various  telescopes  used  and 
the  different  atmospheric  conditions.  With  few  exceptions  the  hole  0.15  was  used 
with  the  6-  and  1 2-inch  and  0.20  with  the  4O-inch. 


CHAPTER   I. — INSTRUMENTS.  7 

In  order  to  use  the  photometer  with  a  6.5-inch  reflector,  a  smaller  tube  was 
provided  carrying  an  ocular  and  a  diagonal  reflecting  plate  to  replace  B.  After 
several  trials  good  images  of  the  real  and  artificial  stars  were  given  by  a  diagonal 
plate  with  surfaces  correct  to  one-tenth  of  a  wave-length,  furnished  by  Mr.  O.  L. 
Petitdidier,  of  Chicago. 


FIG.  2. — CURVE  A  12.    ABSORPTION  OK  WEDGE  V  ON  12-  ANI^O-INCH  REFRACTORS. 


The  use  of  the  instrument  is  very  simple  and  convenient.  The  image  of  the 
star  to  be  measured  (shown  at  H  in  the  drawing)  is  brought  between  the  two 
images  of  the  artificial  star,  and  the  wedge  is  moved  by  the  pinion  R  till  the  light 
of  the  real  star  is  matched  by  E,  the  image  formed  by  reflection  from  the  first 
surface  of  the  plate  B.  The  position  of  the  wedge  is  then  read  on  a  scale  divided 
to  twenty-fifths  of  an  inch,  tenths  of  a  division  being  estimated.  If  now  the 
light  of  a  star  of  known  magnitude  be  measured,  the  only  unknown  quantity  is 
the  absorption  of  the  wedge,  expressed  in  magnitudes. 


8 


RESEARCHES  IN  STELLAR  PHOTOMETRY. 


The  methods  available  for  determining  the  wedge  absorption  can  be  classed 
under  two  heads:  (i)  Measurements  of  standard  stars  whose  magnitudes  have 
been  well  fixed;  (2)  measurements  of  an  artificial  star  whose  light  can  be  reduced 
by  a  known  amount  either  by  (a)  polarization,  (6)  a  revolving  wheel,  (c)  reduced 
apertures  by  stationary  diaphragms.  The  last  method  can  be  used  either  with 
real  or  artificial  stars.  The  method  by  standard  stars  seems  to  give  the  best 
results,  as  it  has  the  great  advantage  that  the  measurements  are  made  under 
the  same  conditions  as  exist  in  practice. 


MAON1TUOC 


FIG.  3. — CURVE  E  6.    ABSORPTION  OF  WEDGE  V  ON  6-iNcn  REFLECTOR. 

The  errors  which  may  be  introduced  by  the  neglect  of  this  precaution  are  dealt 
with  by  King  in  Harvard  Annals,  41,  pages  237  et  seq.,  where  it  was  found  that 
the  mean  absorption  corresponding  to  one  scale  division  was  0.090  with  the  wedge 
almost  in  contact  with  the  aperture,  and  0.130  with  the  wedge  5  cm.  from  the  aper- 
ture. Again,  it  was  found  by  Aitken  and  Maddrill  (Astrophysical  Journal,  22,  147) 
that  the  absorption  measured  with  a  Lummer-Brodhun  photometer,  comparing 
surfaces,  must  be  increased  by  one-quarter  to  equal  the  results  obtained  from  stand- 


CHAPTER   I. — INSTRUMENTS.  9 

ard  stars.  To  avoid  these  sources  of  error,  wedge  V,  which  was  used  in  nearly  all 
the  measures  here  considered,  was  calibrated  by  the  three  following  methods, 
in  all  of  which  the  wedge  was  placed  in  situ,  and  the  conditions  in  actual  practice 
quite  exactly  used1 : 

(1)  Standard  Pleiades  stars,  2,700  settings. 

(2)  Comparison  with  Zollner  photometer,  3,000  settings. 

(3)  Comparison  with  "wheel"  photometer,  500  settings. 

Full  details  of  this  calibration  will  be  published  in  connection  with  the  work 
on  "Determination  of  Standards  for  Faint  Stellar  Magnitude;"  but  in  this  con- 
nection a  comparison  of  the  results  by  the  three  methods  will  give  the  quantities 
used  in  the  reductions  and  at  the  same  time  enable  the  reader  to  form  an  opinion 
of  the  degree  of  accuracy  attained . 

(1)  The  standard  Pleiades  stars  were  measured  with  both  the  6-  and  1 2-inch 
telescopes,  and  the  platted  measures  give  the  absorption  in  the  second  column  of 
Table  3. 

(2)  The  Zollner  polarizing  photometer  was  set  up  in  a  dark  room  opposite  the 
wedge  photometer,   and  the  artificial   stars  compared,   first  by  projecting  the 
Zollner  star  into  the  wedge,  second  by  projecting  the  wedge  star  into  the  Zollner. 
The  mean  of  these  closely  accordant  results  gives  the  absorptions  in  the  third 
column  of  Table  3. 

(3)  The  wedge  star  was  compared  with  an  artificial  star  cut  down  by  a  revolv- 
ing wheel  provided  with  sectors,  giving  the  quantities  in  the  fourth  column. 

The  weighted  mean  of  these  three  determinations  gives  the  values  in  column 
five,  which  are  points  in  the  absorption  curve  corresponding  to  the  scale  readings 
in  the  first  column.  This  curve  is  called  A  12,  and  is  used  in  the  reductions  of 
the  12-  and  40-inch  measures. 

Since  another  ocular  and  diagonal  plate  was  used  in  the  6-inch  measures, 
and  the  appearance  of  the  star  images,  both  real  and  artificial,  was  different, 
it  was  not  considered  allowable  to  assume  that  the  absorption  curve  would  be 
the  same;  therefore  the  measures  of  the  Pleiades  stars  were  repeated  with  the 
6-inch  and  the  comparison  with  the  Zollner  photometer  was  made  with  the  same 
arrangement  of  apparatus  as  used  on  the  6-inch.  The  absorption  curve  found, 
called  E  6,  is  shown  by  column  six  to  differ  enough  from  A  12  to  justify  the 
separate  investigation,  and  at  the  same  time  to  confirm  the  general  features  of 
the  curve  A  12. 

A  few  measures  of  faint  stars  were  made  in  1900  with  wedge  II,  whose 
absorption  curve  derived  from  standard  stars  and  the  "wheel,"  is  given  by 
points  in  the  last  column  of  the  table. 

The  question  of  the  trustworthiness  of  the  adopted  absorption  curve  is  of  the 
highest  importance  in  this  work,  and  demands  the  most  rigid  scrutiny.  The 

1  A  fourth  comparison  with  another  polarizing  photometer  has   since  given  identically  the  same 
absorption  curve. 


10 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


evidence  in  Table  3  may  be  summed  up  as  follows:  (i)  The  results  by  two  inde- 
pendent methods,  standard  stars  and  laboratory  measures,  are  in  good  agreement ; 
the  average  probable  error  of  the  points  platted  on  curve  A  12  being  less  than 
±0.03,  with  a  maximum  of  ±0.07.  (2)  The  laboratory  measures  were  all  made 
by  matching  artificial  stars  which  closely  resembled  the  real  stars. 

TABLE  3. — ABSORPTION  OP  WEDGES  II  AND  V. 


Wedge  V. 

Wedge  II. 

Scale. 

12-inch. 

6-inch. 

Pleiades. 

Zollner. 

Wheel. 

A    12. 

E  6. 

60 

(5.8o) 

(5-49) 

55 

5-34 

5-12 

5.22 

5-32 

50 

4'85 

4.76 

4.80 

4.70 

4-99 

45 

4  39 

4.28 

4.28 

4.33 

4.41 

4.51 

40 

3.80 

3-77 

3-77 

3.78 

3.85 

3-93 

35 

3.14 

3-27 

3  .20 

3  '9 

3  30 

3-35 

30 

2.60 

2-74 

2.61 

2.65 

2.68 

2.85 

25 

2    15 

2.27 

(2.18) 

2.  2O 

2.  13 

2.27 

20 

1.65 

i.  80 

(1-74) 

1.72 

i  .59 

i-5i 

15 

1.07 

i.  08 

1.07 

1.06 

0.93 

0.72 

IO 

0.46 

0.42 

0.50 

o  43 

0.28 

O.  II 

5 

0.06 

0.05 

(o.oo) 

o 

O.O2 

(o.oi) 

A  check  on  the  mean  value  of  the  absorption  is  furnished  by  the  measured 
magnitudes  of  the  stars  near  the  limit  of  vision  of  the  6-inch  telescope.  Table 
4  gives  the  field,  the  estimate  of  the  limit  of  vision,  the  photometric  magnitude 
of  the  limit,  the  correction  for  atmospheric  extinction,  and  the  final  corrected 
magnitude  of  the  limit,  expressed  in  both  the  Harvard  and  Potsdam  systems. 

TABLE  4. 


FiVlH 

M 

lg- 

Corr 

Mag. 

H. 

P. 

H. 

P. 

Z  Cassiopeia 

k 

12  88 

W  Lyra:  

2--?<l 

J3-03 

S  Lyrse  

z 

12    82 

12.93 

SX  Cygni  

-j<n 

13.24 

RU  Herculis  

2<n 

12  -34 

V  Cassiopeia  

Q 

13.07 

J3  34 

12.97 

Mean  

12.75 

CHAPTER  II. 


R.  A.  oh 


103  T  ANDROMEDA. 
io.os;  Dec.   +26°  26'  27"  (1900). 


The  variability  of  this  star  was  discovered  by  Anderson  in  1  893  and  observations 
began  soon  after  the  receipt  of  the  Astronomische  N  achrichten  No.  3202  contain- 
ing the  announcement.  The  literature  concerning  the  star  is  given  so  completely 
in  the  forthcoming  catalogue  of  the  Gesellschaft  committee,  that  it  is  unnecessary 
to  repeat  it  here.  The  light  changes  are  unusually  regular,  the  maxima  and  minima 
being  both  well  denned.  At  present  the  period  seems  to  be  lengthening. 

The  comparison  stars  have  been  measured  with  the  photometer,  the  residuals 
being:  For  the  catalogue  stars,  ±0.03;  for  the  stars  measured  with  the  6-,  12-, 
and  4o-inch,  respectively,  ±0.08,  ±0.09,  and  ±0.11  magnitude. 

Detailed  explanations  follow  for  the  tables  and  figures  giving  the  photometric 
and  visual  results  for  this  star.  For  the  other  eleven  variable  stars  given  in 
Chapters  III  to  XIII  explanations  are  only  given  for  the  few  particulars  in 
which  the  tables  differ  from  those  for  T  Andromedae.  The  arrangement  of 
the  tables  is  as  follows  :  First,  the  data  for  the  identification  of  the  comparison 
stars  with  a  summary  of  the  magnitude  results  used  in  the  reductions,  Tables  5,6, 
and  7;  second,  the  photometric  measures  in  detail,  Table  8;  third,  reduction 
constants  and  summary  of  photometric  results,  Tables  9  and  10;  fourth,  visual 
observations  of  the  variable,  with  reductions  to  photometric  magnitude,  and 
residuals  from  the  mean  light  -curve,  Table  1  1  ;  fifth,  data  for  formation  of 
mean  light-curve,  with  residuals  for  the  twelve  parts  of  each  separate  curve, 
Table  12;  sixth,  observed  maxima  and  minima,  Table  13. 

TABLE  5.  —  STANDARD  MAGNITUDE  STARS. 


Star. 

B.  D.  No. 

1900. 

Color 
P.  DM. 

Magnitude. 

Residuals. 

R.  A. 

Dec. 

Catalogue. 

Measured. 

From  Cats. 

3 
Nights 
inter 
se. 

H.  C.  O. 

P.  DM. 

H. 

P. 

H. 

P. 

A 
B 
a 

O 

+  25     34 
+  25     29 
+  26     40 

Mean  .... 

h   m    s 
o  14  10 
o  13  18 
o  16  18 

O             t 

+  25  54-7 
+  25  36.  i 
+  26  23.7 

GW+ 

W+ 
WG+ 

7.67 
7.21 

8.20 

7.76 
7.42 

8.12 

7.6: 

7-47 
7.98 

7.69 

7  55 
8.06 

-    6 
+  26 

—  22 

-    7 
+  13 
-    6 

±4 

±2 

±3 

7.69 

7-77 

7.69 

7.77 

±18 

±   9 

±3 

Table  5  gives,  for  the  standard  magnitude  stars,  the  Bonn  Durckmusterfang 
numbers,  the  position  for  1900,  the  Potsdam  color,  and  the  catalogue  magnitudes 


ii 


12 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


which  form  the  basis  of  the  photometric  work.  The  "H.  C.  O."  values  are  taken 
from  the  Harvard  Annals,  45,  the  "P.  DM."  from  Potsdam  Publications,  vols.  9, 
13  and  14.  Then  follow  the  measured  magnitudes  and  residuals  which  result  from 
Table  10,  and  will  be  considered  in  that  connection.  As  all  the  measured  magnitudes 
are  based  on  these  three  catalogue  stars  it  follows  that  the  measured  magni- 
tude of  each  star  expressed  in  the  Potsdam  system  will  be  0.08  greater  numerically 
than  its  magnitude  in  the  Harvard  system. 

TABLE  6. — COMPARISON  STARS  IN  B.  D.  CATALOGUE. 


B.  D. 

1855- 

B.  D. 

1855. 

No. 

Mag. 

R.  A. 

Dec. 

No. 

Mag. 

R.  A. 

Dec. 

i 

0 

h  m  s 

0       / 

O 

h  m  s 

0      / 

d 

4-26  37 

8.8 

o  13  33 

4-26  10.0 

e 

+  26  46 

9-4 

o  15  47 

+  26  22.9 

a 

4-26  40 

7-5 

o  13  58 

4-26   8.7 

c 

4-26  47 

9-1 

o  15  50 

4-26  18.4 

I 

4-25  40 

9-5 

o  14  19 

+  25  58.3 

> 

+  26  48 

9-4 

o  16  10 

+  26  12.1 

b 

4-  26  42 
% 

8.1 

o  14  27 

4-26  23.4 

Table  6.  As  a  few  of  the  brighter  comparison  stars  are  not  within  the  limits 
of  the  photographic  charts,  Table  6  gives  the  B.  D.  numbers,  magnitudes,  and 
places  for  1,855  of  the  stars  in  that  catalogue  not  in  Table  5. 

TABLE  7.— COMPARISON  STARS  FOR  T  ANDROMED-B  (IN  ORDER  OF  RIGHT  ASCENSION). 


Star. 

Coordinates  from  Variable. 

Light 
Scale, 
Steps. 

Magnitude. 

R.  A. 

Dec. 

Measured. 

From  Curve. 

H. 

P. 

H. 

P. 

// 

s 

// 

d 

—  1017 

-74.0 

-    30 

34-7 

9.12 

9.20 

q 

-   770 

-56.1 

4-   41 

H-3 

12.2 

is.  3 

a 

-   698 

-50.8 

—  122 

42.0 

7.98 

8^06 

P 

-   679 

-49.4 

+      19 

15-3 

12.  I 

12.2 

n 

-   617 

-44-9 

-297 

17.1 

II.  8 

II.9 

0 

-    55° 

—  40.0 

-173 

16.3 

II.9 

12.  0 

s 

-   411 

-29.9 

-873 

25.6 

10.32 

10.40 

r 

-   389 

-28.3 

+     85 

10.3 

12.8 

12.9 

b 

-   316 

-23.0 

+  690 

39-0 

's:72 

8.80 

h 

—    290 

—  21  .  I 

-     23 

18.9 

II-5-i 

II  .62 

I 

-    259 

-18.9 

—  690 

26.5 

10.15 

10.23 

y 

-     85 

-    6.2 

4-   44 

14.40 

14.48 

X 

—        21 

-    i-5 

4-174 

IO.O 

13.12 

13.20 

w 

4-      30 

4-     2.2 

4-103 

13-68 

13-76 

u 

+     33 

4-    2.4 

4-226 

13.22 

13  30 

z 

4-    108 

+   7.9 

4-   62 

14.08 

14.  16 

m 

+    157 

4-11.4 

4-8oo 

20.5 

11.28 

11.36 

t 

4-    196 

+  14-3 

4-420 

12.3 

11.66 

11.74 

k 

4-    227 

4-16.5 

4-io6 

14-3 

11.85 

11-93 



e 

+    793 

+  57-7 

+  659 

30-7 

10.  20 

10.28 

c 

+    835 

4-60.8 

+  394 

33.6 

9-5i 

9-59 

} 

4-1125 

4-81.9 

4-n8 

29.5 

9-97 

10.05 

Table  7  collects  the  data  for  position  and  magnitude  of  all  the  comparison 
stars  used.  The  second  and  fourth  columns  give  the  rectangular  coordinates  from 
the  variable  in  seconds  of  arc;  the  third  column  expresses  the  R.  A.  coordinate 


STELLAR    PHOTOMETRY. 


N 
om 


PLATE   2. 


+20' 


.ei 


j 


tu 


•Xa 


•  W. 

z 


© 


y 


df 


»a,e 


•  nt 


•  So 


+  10' 


10' 


Scale,  i  mm=  13. "7. 


1903  February  1 6. 


103   T   ANDROMEDvE. 
R.  A.  oh  i7«n  IQS.O.     Dec.  +26°  26'  27",  1900. 


CHAPTER   II. — T   ANDROMEDA. 


in  seconds  of  time.  The  fifth  column  gives  the  brightness  of  the  star  in  steps  of 
the  light-scale,  which  result  from  the  observations  in  Table  n,  and  will  be 
explained  in  that  connection.  The  last  four  columns  give  the  magnitude,  either 
"measured"  with  the  photometer  or  read  from  the  magnitude-curve  (fig.  4). 
In  each  case  the  heading  "H."  indicates  the  Harvard,  and  "P."  the  Potsdam 
system.1  The  adopted  values  for  stars  measured  with  both  6-  and  12 -inch  are 
taken  from  the  1 2-inch. 

TABLE  8. — 103  T  ANDROMEDA. 
PHOTOMETER  MEASURES  OF  COMPARISON  STARS. 

6-INCH. 


1904  October  15.                                                                            Fair  to  good,  quiet,  a  little  dull. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

h    m 

I    OI 

i   24 

o 

20 

22 

c 
e 
b 
d 
a 
I 
s 
A 
B 
B 
A 
I 
a 
d 
b 
e 
c 

26.7  27.3  27.1 
38.8  39.0  38.1 

22.6    24    2    23.0 
24.2    26.2    26.3 
15.7     16.3     16.4 

34-8  35-2  36.0 
36.8  36.7  36.3 
13.8  14.0  13.9 

13.  I     12.2     13.2 

12.9   13.7   12.8 
15.1   14.0  14.0 

36.1  35-9  36.3 
16.5   17.2   17.2 
25.3  26.4  26.9 
25.8  25.8  25.1 
36.1  37.2  36.7 
28.3  27.8  28.5 

27.03 
38.63 
23.27 

25-57 
16.13 

35-33 
36.60 
13-90 
12.83 

I3-I3 
14.70 
36.  io 
16.97 
26.20 
25-57 
36.67 
28.20 

27.62 
37-65 
24.42 
25.89 
16.55 
35-72 

14-30 
12.98 

2.41 
3-62 
2.07 
2.23 
1.16 
3-42 
3-52 
0.84 
0.63 

9.22 
10.43 
8.88 
9.04 

7-97 
10.23 

10-33 
7-65 
7-44 

9-30 
10.51 
8.96 
9.12 
8.05 
10.31 
10.41 
7-73 
7-52 

1904  October  27.                                                                                        Fine,  moon  rising  at  end. 

31    36 

21   57 

37 

34 

B 
A 
s 
I 
a 
d 
b 
e 
c 
c 
e 
b 
d 
a 
1 
A 
B 

9-7   io.  i     95 
11.7   11.9  ii  .8 
32.0  31.9  31.8 
32-8  33-4  33-4 
13.0  14.7  14.2 
25.  i   25.8  25.0 

21  .0    21  .2    21.4 

30-9    31-3    32-1 
24.0    25.2    25.0 
25-5    25.9    25.3 
32.5    31.6    31.9 

19.4  20.  6  19.8 
23.2  23.3  24.5 
14.2  13.6  13.3 
32.0  33.3  33.0 

II  .2    lO.g    II.  I 
9.8    II.  2    IO.7 

9-77 
11.80 
31.90 
33-20 
13  97 
25-30 

21  .  2O 
31-43 
24-73 
25-57 
32.00 

19  93 
23-67 
13-70 
32-77 
ii  .07 

10-57 

io.  17 
11.44 

0.30 

0.44 
2.92 
3-05 
0.76 
2.08 
1.66 
2.89 
2-15 

7-49 
7-63 

IO.  II 

io.  24 
7-95 
9-27 
8-85 
10.08 
9-34 

7-57 
7-7' 
io.  19 
10.32 
8.03 
9-35 
8-93 
io.  16 

9-42 

32.99 
13-84 
24.49 
20.57 
3i-72 
25-15 

'The  letters  "H.  C.  O."  and  "P.  DM"  indicate  that  the  magnitudes  are  taken  directly  from  the 
respective  catalogues.  The  letters  "H."  and  "P. "indicate  measurements  by  the  writer,  expressed  in  the 
corresponding  systems. 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 
TABLE  8. — 103  T  ANDROMED* — Continued. 


1904  October  30.                                                                                                                         Good- 

Sidereal 
Time. 

h    m 

21    OO 
21    24 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings.; 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

O 

44 
40 

B 
A 
s 
L 
a 
d 
b 
e 
c 
c 
e 
b 
d 
a 
I 
A 
B 

11.7  11.4  ii  .6 
ii.  o  ii.  6   ii.  i 
35.0  36.0  35.3 
32-9  33-8  33.1 
14.7   14.6   14.5 
25.8  25.8  25.1 
18.8  19.2   19.0 
34.0  34.0  34.1 
26.5  26.2  27.1 
26.8  26.3  26.9 
33-0  33-3  33-3 
21.3  20.7  21.3 
26.0  26.  7  26.0 
14.9  15.4  14.4 

33-1  33-°  33-o 
ii.  6  ii.  8   ii.  i 
9.8  10.2   10.2 

"•57 
11-23 

35-43 
33-27 
14.60 

25-57 
19.00 

34-03 
26.60 
26.67 
33-20 

21  .  IO 
26.23 
14.90 

33  03 
11.50 
10.07 

10.82 
".37 

33-15 
14-75 
25-95 
20.05 
33-62 
26.64 

0-37 
0-43 
3-39 
3-07 
0.90 
2.24 
'•59 
3.13 
2.30 

7-49 
7-55 
10.  51 

TO.  19 
8.02 
9.36 
8.7I 
10.25 
9.42 

7-57 
7.63 
10.59 
10.  27 
8.  10 

9-44 
8.79 

10-33 
9  50 

1904  September  n.                                          12-INCH.                                                              Good. 

20  23 
20  48 

49 
45 

d 
b 
e 
c 
t 
k 

X 

I 
I 

X 

k 
t 

c 
e 
b 
d 

15.  i   14.8  16.0 
ii  .9  12.3  12.4 
23.5  24.8  23.9 
17.3  18.0  17.5 
39-7  39-9  4°-0 
39.2  40.7  39-9 
53-8  54-7  54-3 
22.9  23.  i   23.2 
23.7  22.9  23.7 

54-2  54-7  54-2 
41.1  41.7  40.9 
40-3  39-9  40-1 
17.9  19.0  17.7 
24.3  26.2  25.7 
ii.  8   ii.  i    11.7 
15.0  14.8  15.1 

15-30 

12.  2O 
24.03 
I7.6O 
39-87 

39-93 

54-27 
23.06 

23-43 
54-37 
41-23 
40.  10 
18.20 
25-40 
11-53 
H-97 

15-  14 
11.87 
24-72 
17.90 

39-99 
40.50 

54-32 
23-25 

1.07 
0.88 
2.17 
i-43 
3.78 
3.85 
5-17 
2.05 

9.O6 

8.87 

10.  16 
9.42 
11.77 
ii  .84 
13.  16 
10.04 

9.14 

8.95 
10.  24 
9-50 
11.85 
ii  .92 
13-24 

10.  12 

1904  October  31.                                                                                                                         Good. 

21  5° 
22  18 

34 
29 

e 
c 
t 
k 

X 

V 

I 

d 
b 
£ 

Oa\ 

d 

I 
X 

k 
t 
c 

e 

2O.  8    21  .  I    21  .  I 

15.2  16.2  16.7 
32-8  33.1   34-0 
37-6  37-3  37-6 
50.8  50.2  51.4 
36.7  37-2  37-9 

22.  O    21  .9    21.8 
12.5    13.2    12.9 

5-4    6-6     6-7 
14.9  15.7  14.1 
14-9  '5-7  15-0 
12.9  12.9  12.9 

2O.9    21  .9    21.8 

47.2  49.2  49.8 
34.0  34.2  34.9 
34-2  33-7  34-0 
14.9  15.2  14.8 
20.7  20.  i   20.  8 

21  .OO 
16.03 

33-37 
37-50 
50.80 
37-28 

21  .90 
12.87 
6.23 
14.90 
15.20 
12.90 
21-53 
48.73 

34-37 
33-97 
14-97 
20.53 

20.72 
15-50 
33.67 
35-94 
49-77 

21.72 
12.89 

1-79 

I  .  12 

3-04 

3  29 
4-78 
3-46 
1.90 
0.76 

O.  12 

1.07 

10.22 
9-55 

"•47 

11.72 
13.21 
11.89 
10.33 
9.19 

8.55 
9-50 

IO.3O 
9.63 

"•55 
11.80 

13-29 
11.97 
10.41 

9-27 
8.63 

9  59 

15.05 

CHAPTER  II. — T  ANDROMEDA. 
TABLE  8. — 103  T  ANDROMED/B — Continued. 


1904  November  2.                                                                           Fair,  a  little  dull,  and  unsteady. 

Sidereal 
Time. 

Zen. 

Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

h    m 
21  30 

21   50 

0 

38 

34 

{ 

d 
b 
e 
c 

t 

X 

k 

V 

k 
t 
c 
e 
b 
d 
I 

28.9  29.  i   29.4 
20.3  20.3  20.3 
16.7   16.  7   16.0 
32.2  32.0  30.8 
25.0  25.3  24.8 
44.2  44.7  44.8 
60  ±        

29.13 
20.30 
16.47 
31.67 
25-03 
44-57 

30.10 
20.27 
16.55 
31-54 
24.38 

45-15 

60.  ± 
47.60 

2.67 
1.74 
1.27 
2.82 
2-15 
4-35 
5-6± 
4-59 
4-44 

10.07 
9.14 
8.67 

IO.  22 

9-55 
"•75 
I3-0± 
11.99 
u  .84 

10.15 
9.22 

8.75 
10.30 

9  63 
11.83 

13-  1± 
12.07 
ii  .92 

47.2  47.9  47.0 
46.0  45.9  46.5 
48-2  47-7  47-6 
45-5  45-9  45-8 
23.2  24.0  24.0 

3i-3  3i-5  31-4 
15.9  17.2   16.8 
20.4  20.  i   20.  2 
31.9  31.0  30.3 

47-37 
46-13 
47-83 
45-73 
23-73 
3I-40 
16.63 
20.23 
31-07 



1905  January  14.                                              40-INCH.                                              Fair,  unsteady. 

4  27 

52 

t 
k 

2 
W 
•Va, 
X 

u 
u 

X 

W 

z 

k 
t 

34-i   34-7  33-7 
33-4  33-7  33-i 
56.7  58.7  58.0 

53-0  51   7  5i-5 
9.5     8.4  ji.  i 
44-3  44-5  44-9 
47-8  46-4  45-9 
46  .  7  46.2  46  .  7 
41  .0  42.9  42.  i 
51.3  51.8  51.9 
57-8  57.1   57.3 
32-5  32-7  32-4 
3i  7  3i-9  33  o 

34-17 
33-40 
57-8o 
52.07 
9.67 
44-57 
46-77 
46.53 
42.00 

51-67 
57  40 

32.53 
32.20 

33-  «8 
32-98 
57-6o 

5I-87 

43-28 
46.65 

3.00 
2.96 
5-37 
4-99 
0.41 
4-13 
4  50 

11.85 
II.  8l 

14.  22 

13-84 
9.  26 
12.98 

«3-35 

H-93 
11.89 
I4-30 
13-92 
9  34 
13-06 

'3-43 

1905  January  28.                                                                                                                         Good. 

4  22 
4  38 

57 

t 
k 

z 
«' 

y 

X 

u 
u 

X 

y 

W 

z 

k 
t 

20.  0    21  .2    2O.7 
22.  O    21  .9    22.3 
41.2    41.3   40.7 
36.1    37.0   36.4 
42.7    43.6    43.3 
31.9    32.1    31.7 

34-0  33-9  34-i 
33-i  33-8  32-8 
30.0  31.0  31.3 
42.5  43-3  43-1 
36-3  35-o  35-5 
39.8  40.0  41  .0 
19.8  20.3  19.9 
19.8  20.9  20.  o 

20.63 
22.07 
41.07 
36-50 
43-20 
31.90 
34-00 
33-23 
30-77 
42-97 
35-6o 
•40.27 
20.00 
20.23 

20.33 
21.04 
40.67 
36-05 
43.08 

31.34 
33-62 

1.74 
1-83 
3-85 
3-3i 
4.11 
2.79 
3-05 

11.83 
ii  .92 

13-94 
I3-40 
14.20 
12.88 
I3-I4 

ii  .91 

12.  OO 

14.02 

I3-48 
14.28 
12.96 
13-22 

i6 


RESEARCHES   IN   STELLAR    PHOTOMETRY. 


TABLE  8. — 103  T  ANDROMEDA — Continued. 


1905  February  25.                                                                                                  Fair  to  good,  low. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3 

Mean  of  6. 

H. 

P. 

h  m 

O 

t 

22.  2    22.  I     22.3 

22.  2O 

21.68 

1.89 

ii  .89 

11.97 

k 

21.3    22.4    22.7 

22.  13 

20.46 

i-75 

"-75 

11.83 

z 

41.5    42.3    42.9 

42-23 

42.82 

4.08 

14.08 

14.  16 

w 

4°-3  39-3  40-2 

39-93 

40.05 

3-79 

'3-79 

13-87 

Va, 

ii  .  5   10.4  11.4 

II  .  IO 

10.82 

0-53 

10-53 

10.  61 

y 

48.2  48.1  48.9 

48.40 

47-76 

4.60 

14.60 

14.68 

X 

32.5  33-8  32-9 

33-07 

33-25 

3-00 

13.00 

1  3  .  08 

u 

35-2  35-i  34-7 

35-00 

34-68 

3.16 

13.  16 

13-24 

X 

32.8  34.2  33.3 

33-43 

IO     ^T. 

k 

19     8O 

35 

t 

20.  O    21.7    21.8 

21.17 

Table  8  gives  the  detailed  photometric  measures  and  reductions  of  the  com- 
parison stars  in  Table  7,  based  on  the  stars  in  Table  5.  The  series  measured  on 
three  nights  with  the  6-inch  includes  the  three  catalogue  stars  A,  B,  and  a,  also 
the  six  comparison  stars,  b,  c,  d,  e,  I,  and  s.  A  complete  series  consists  of  three 
settings  on  each  star  in  the  list,  followed  immediately  by  three  more  settings  on 
the  stars  in  reverse  order.  Thus  the  mean  of  the  times  is  the  same  for  each  star 
and  any  progressive  changes  in  the  real  or  the  artificial  star  will  be  eliminated. 
In  the  seventh  column  there  are  two  mean  scale  readings  for  each  star,  which 
are  united  into  the  single  mean  of  the  eighth  column.  The  ninth  column  contains 
the  values  of  C  (curve  reading)  corresponding  to  each  mean  scale  reading.  These 
are  taken  from  the  absorption  curves,  E  6  for  the  6-inch  and  A  12  for  the  12- 
and  4O-inch,  and  express  the  relative  magnitudes  of  the  stars  as  explained 
below.  To  convert  C  into  magnitudes  in  the  system  of  the  catalogue,  it  is 
increased  by  the  quantity  M0  taken  from  Table  9.  For  example,  on  October  15 
the  mean  C  for  the  three  standard  stars  is  0.88;  the  mean  of  their  magnitudes 
from  the  H.  C.  O.  Catalogue  is  7.69;  the  difference  in  the  two  quantities,  called 
MOI  is  6.8 1.  If  MJ  be  added  to  each  C,  the  mean  of  the  sums  for  the  three  stand- 
ard stars  will  agree  with  the  mean  of  their  catalogue  magnitudes,  and  the  separate 
sums  will  preserve  the  relative  magnitudes  as  measured.  The  quantity  M0  is 
the  magnitude  of  the  zero  reading  on  the  absorption  curve,  and  when  increased 
by  the  C  of  each  star  will  give  the  magnitude  in  the  system  used.  In  the  example 
we  are  using  the  M0  in  the  Potsdam  system  is  6.89.  Adding  these  values  of  M0 
to  C  we  have  the  last  two  columns  of  Table  8,  the  measured  magnitudes  in  the 
H.  C.  O.  and  P.  DM.  systems. 

The  sidereal  time  and  zenith  distance,  given  in  the  first  two  columns  of  Table  8, 
serve  to  show  that  no  correction  is  needed  for  change  in  atmospheric  absorption 
due  to  difference  in  zenith  distance  between  the  standard  stars  and  the  stars  to 
be  measured.  For  example,  on  October  15,  when  the  field  was  near  the  meridian, 


CHAPTER   II. — T   ANDROMEDA. 


the  mean  zenith  distance  of  the  three  standard  stars  was  £°  less  than  that  of 
the  measured  stars.  At  zenith  distance  21°  a  difference  of  £°  corresponds  to  a 
change  of  o.ooi  magnitude  in  the  atmospheric  absorption,  which  is  negligible. 
The  stars  measured  with  the  12-  and  4o-inch  were  all  within  20'  of  the  variable,  so 
that  the  correction  would  be  even  less.  The  subscript  01,  appended  to  the  star 
letter,  shows  that  the  star  was  measured  through  one  shade  glass,  which  increases 
the  magnitude  numerically  by  0.75  for  the  6-inch  and  0.84  for  the  12-  and  4o-inch 
measures. 

TABLE  9. — 103  T  ANDROMEDA.    CONSTANTS  FOR  REDUCTION  AND  COMPARISON  WITH  CATALOGUE 

MAGNITUDES. 


6-INCH. 

Star. 

October  15. 

October  27. 

October  30. 

C. 

Obs.  Mag. 

4  Mag. 

C. 

Obs.  Mag. 

4  Mag. 

C. 

Obs 

Mag. 

4  Mag. 

H. 

P. 

H.       P. 

H. 

P. 

H. 

P. 

H. 

P. 

H.         P. 

A 
B 
a 

Means. 

Hi.... 

0.84 
0.6' 
i.  if 

7.65 
7-44 
7-97 

7-73 
7.52 
8.05 

—  .02  —  .03 

+  .23  +  .10 

-  .23  -  .07 

0.44 
0.30 
0.76 

7-6 
7-4' 
7.9 

3    7-7' 
J    7-57 
5    8.03 

-  .04 

+  .  2£ 

-  -25 

-  -05 
+  •15 
—  .09 

0-43 
o.37 
0.90 

7-5, 
7-4< 
8.0: 

i    7.63 
)    7-57 
8.10 

-.12  -.13 
+  .28  +  .15 

-  .18  -  .02 

o.8f 

7.69 
6.81 

7-77 
6.89 

±  .16  ±  .07 

0.50 

7.6< 

)    7-77 
)    7-27 

±•19 

±  .  10 

0-57 

7.6c 

7.1; 

7-77 
7.  20 

±  .19  ±  .10 

12-INCH. 

40-INCH. 

Star. 

Mag. 
6-inch. 

C. 

Star. 

Mag. 
12-inch 

C. 

Sept.  ii.  Oct.  31. 

Nov.  2. 

Jan.  14. 

Jan.  28.      Feb.  25. 

6  

8.81 

9-33 
9.22 

0.88          o  19 

1.43              I.  12 

1.07         0.76 

1.27 
2-15 

i-74 

k 

11.85 
11.66 
13.  12 

2.96 
3.00 

1.83            i-75 
i  .  74            1-89 
2.79            300 

c  

t 

d  

X               -  - 

Mean 
Mean 

Mo    .   . 

r 

Mean 
Mean 
M0.  .  . 

C.  .  . 

1.13          0.69 

9.  12             9.  12 

7-99          8.43 

1.72 
9.12 
7.40 

3.36 

12.  21 

8.85 

2.  12                 2.21 
12.21                12.21 

10.09           10.  oo 

Mag. 

9.  12 

Mag. 

12.21 

Table  9  contains  the  values  of  C,  the  reading  from  the  absorption-curve  of 
the  wedge.  From  the  mean  C  we  derive  the  M0  used  in  the  reductions.  In  the 
first  part  of  the  table  (6-inch)  the  observed  magnitudes  of  the  three  standard  stars 
are  given,  both  in  the  Harvard  and  Potsdam  systems,  in  the  columns  headed  H. 
and  P.  Subtracting  the  catalogue  magnitudes  in  Table  5  from  these  observed 
values  gives  the  residuals  tabulated  under  "  d  Mag."  for  each  system.  The  con- 
clusions which  may  be  drawn  from  these  residuals  are  discussed  in  Chapter  XIV.  As 
the  measures  with  the  12 -inch  are  based  on  the  standards  fixed  with  the  6-inch, 
the  second  division  of  the  table  contains  the  6-inch  magnitudes  of  the  three 
standard  stars  b,  c,  and  d,  from  Table  10,  and  the  values  of  C  found  on  the  three 
nights  with  the  resulting  values  of  M0.  Similarly  the  4o-inch  division  of  the 
table  gives  the  magnitudes  derived  with  the  1 2-inch  for  k,  t,  and  x,  with  C  and 
M  0.  In  the  last  two  divisions  the  magnitudes  are  given  in  the  Harvard  system 
only,  to  express  them  in  the  Potsdam  system  add  0.08  as  shown  in  Table  5. 


i8 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABLE  10. — 103  T  ANDROMEDA.    MEAN  MAGNITUDES. 

6-INCH. 


Star. 

October  15. 

October  27. 

October  30. 

Mean. 

Mag. 

A  Mag. 

Mag. 

J  Mag. 

Mag. 

J  Mag. 

Mag.  H- 

Mag.  P. 

A  Mag. 

A              

7.65 
7-44 
7-97 

+  0.04 
-0.03 

-O.OI 

7-63 
7-49 
7-95 

+  O.O2 
+  0.02 
—  0.03 

7-55 
7-49 

8.02 

—0.06 

+  O.O2 
4-O.O4 

7.61 

7-47 
7.98 

7.69 

7-55 
8.06 

±0.04 
±0.02 
±0.03 

B          

Mean  

7.69 

7-77 

±0.03 

6 

8.88 
9.22 
9.04 
10.43 
10.23 
10-33 

+  0.07 

—  O.  II 

-0.18 
+  0.18 

+  O.OI 
4-O.OI 

8.85 

9-34 
9.27 
10.08 
10.24 

IO.  II 

+  0.04 

4-O.OI 

+  0.05 
-0.17 

+  O.O2 
—  O.2I 

8.71 
9.42 
9-36 
10.25 
10.  19 
10.51 

—  O.  IO 
—  O.O9 

+  o.  14 
o.oo 
—  0.03 
+  o.  19 

8.81 
9  33 

9.  22 
10.25 
IO.22 
10.32 

9.69 

8.89 
9.41 
9-30 
10.33 
10.30 
10.40 

±0.07 
±0.07 

±O.  12 
±0.12 
±O.O2 
±0.14 

d      

1             

9-77 

±0.09 

12-INCH. 

Star. 

September  n. 

October  31. 

November  2. 

Mean. 

Mag. 

J  Mag. 

Mag. 

J  Mag. 

Mag. 

JMag. 

Mag.  H. 

Mag.  P. 

J  Mag. 

b       

8.87 
9.42 
9.06 

+  0.15 
—  0.09 
—  0.06 

8.62 

9-55 
9.19 

—  o.  10 
+  0.04 
+  0.07 

8.67 

9-55 
9.14 

—  0.05 
+  0.04 

4-O.O2 

8.72 
9-5i 

9.  12 

8.80 

9  59 
9.20 

±O.  IO 

±0.06 
±0.05 

d                  

9.12 

9.20 

±0.07 

e  

10.  16 
11.84 
10.04 
11.77 
13.16 

—0.64 

—  O.OI 
—  0.  II 
+  O.  II 

+  0.04 

IO.22 
11.72 
10.33 
11.47 
13.21 

+  O.O2 

-0.13 

+  0.18 
—  o.  19 
+  0.09 

IO.22 

11.99 

10.07 
"•75 
»3-°± 

4-O.O2 

4-0.  14 
-0.08 
+  0.09 

—  O.  12 

IO.2O 
11.85 
10.15 

11.66 
13.12 

10.28 

"•93 
10.23 
11.74 
13.20 

±0.03 
±0.09 

±O.  12 

±0.13 
±0.08 

k           

/          

t  

Mean  .      ... 

11.40 

11.48 

±0.09 

40-INCH. 

Star. 

January  14. 

January  28. 

February  25. 

Mean. 

Mag. 

J  Mag. 

Mag. 

d  Mag. 

Mag. 

JMag. 

Mag.  H. 

Mag.  P. 

4  Mag. 

k     

n.  81 
11.85 
12.98 

—  O.O2 
—  O.OI 

+  0.03 

ii  .92 

11.83 
12.88 

+  0.09 
-0.03 
—  0.07 

"•75 
ii  .89 
13.00 

—  0.08 
4-0.03 
4-0.05 

11.83 
11.86 
12.95 

11.91 
11.94 
13-03 

±0.06 

±0.02 

±0.05 

t  

Mean  

12.21 

12.29 

±0.04 

u      ...       .... 

J3-35 
13-84 

+  0.13 

+  0.16 

I3-I4 
'3  40 
14.  20 

13  94 

-0.08 
-0.28 

—  O.2O 
+  0.14 

13.16 

13-79 
14.60 
14.08 

—  0.06 
4-0.  ii 

4-O.2O 

o.oo 

13.22 
13.68 
14.40 
I4.O8 

I3-30 
I3-76 
14.48 
14.  16 

±0.09 
±0.18 
±o.  20 
±0.09 

TV        

y  

2       

14.22 

+  0.14 

Mean  

13    85 

'3  93 

±0.14 

CHAPTER   II. — T   ANDROMEDA.  19 

Table  10  collects  the  magnitude  results  for  each  night  from  Table  8  and  forms 
the  means.  The  magnitudes  for  the  separate  nights  are  expressed  in  the  Harvard 
system,  and  followed  by  the  column  "J  Mag."  giving  the  residuals  from  the 
mean  of  three  nights.  The  columns  of  means  give  the  magnitude  in  both  systems, 
and  lastly  the  means  of  the  separate  residuals. 

Table  n  gives  the  comparisons  of  the  variable  by  Argelander's  method 
(including  a  few  photometric  and  photographic) ,  the  resulting  photometric  magni- 
tudes of  the  variable,  and  a  comparison  with  the  mean  light-curve.  The  Central 
Time  (6  hours  west  of  Greenwich)  is  given  in  the  third  column  to  the  nearest  hour, 
but  as  the  records  were  usually  made  to  the  nearest  quarter  hour,  the  decimal 
of  the  Julian  day  in  the  fourth  column  is  carried  farther  and  sometimes  differs 
by  one  or  two  hundredths  from  the  hour  in  column  three.  In  the  fifth  column, 
"Aperture,"  6  stands  for  the  6^-inch  Brashear  reflector  (clear  aperture  equivalent 
to  6.2  inches  —  15  cm.),  3  for  the  same  with  diaphragm,  12  and  40  for  the  Yerkes 
refractors  (30  and  102  cm.  respectively),  24  for  the  60  cm.  reflector. 

The  comparisons  in  the  seventh  column,  unless  otherwise  stated,  were  made 
by  Argelander's  method,  the  comparison  stars  being  denoted  by  letters,  -v  stand- 
ing for  the  variable.  The  stars  compared  were  brought  equally  distant  from  the 
center  of  the  field  and  the  head  turned  till  the  line  joining  the  eyes  was  parallel 
to  that  joining  the  stars.  Then  by  glancing  from  one  star  to  the  other  the  interval 
in  steps  was  estimated.  In  the  records  the  brighter  star  is  given  first;  cm  is  read 
"c  is  one  step  brighter  than  the  variable;"  b^-^v,  b  is  four  or  five  steps  brighter 
than  the  variable.  When  the  variable  was  not  seen  the  limiting  magnitude  is 
usually  estimated  from  the  faintest  comparison  star  visible,  for  example  "limit 
4<>"  means  that  the  limit  of  visibility  is  four  steps  fainter  than  e. 

The  reductions  in  columns  8,  9,  and  10  were  made  as  follows:  (i)  The  light 
scale  was  formed  in  the  usual  manner  from  all  the  step  intervals  in  column  7, 
with  the  results  given  in  the  fifth  column  of  Table  7.  (2)  Each  comparison  in 
the  seventh  column  then  gives  the  brightness  of  the  variable  in  steps,  columns. 
For  example,  on  the  first  date,  since  6=  39.0  steps,  the  comparison  64-57;  gives  34.5 
for  the  brightness  of  the  variable.  (3)  To  form  the  mean  step  values  for  the 
ninth  column,  if  the  estimated  interval  is  greater  than  two  or  three  steps  the  results 
are  weighted  inversely  as  the  interval.  (4)  To  obtain  the  corresponding  photometric 
magnitudes  given  in  the  tenth  column  in  the  Harvard  system,  recourse  is  had 
to  the  "Magnitude-Curve"  (fig.  4).  Using  the  data  in  Table  7,  for  the  stars 
measured  with  the  photometer,  the  step  values  are  platted  as  ordinates  and 
the  magnitudes  as  abscissas.  (5)  A  smooth  curve  is  drawn  through  the  platted 
points,  giving  from  the  step  values  in  the  ninth  column  the  magnitudes  in  the 
tenth.  The  step  values  of  the  stars  not  measured  are  entered  in  crosses  on  the 
magnitude-curve,  and  the  resulting  magnitudes  are  given  in  Table  7,  eighth  and 
ninth  columns. 


2O 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABLB  n. — 103  T  ANDROMEDA.    VISUAL  OBSERVATIONS  OP  THE  VARIABLE. 


No. 

Date. 

Ocular. 

I 

I 

<! 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing 

I 

J  Mag 

Month 
and  Day. 

Hour 

:.  s.  T. 

Julian 
Day 
G.  M.  T. 

Steps. 

34-4 
32.1 

36.5 

Mag. 

i 

3 

3 

4 
5 
6 

7 
8 

9 

10 

it 

12 
13 

14 

15 
16 

17 
18 

19 
20 

21 
22 

23 

24 
25 
26 

27 

28 
29 

30 

3l 
32 
33 
34 

3I 
3<5 

37 
38 
39 
40 

41 
42 

1894 
Mar.    15 
17 

21 

23 
26 

Apr.     i 

3 
ii 

15 

24 
27 
May     2 
7 
24 
June  30 
July  29 
Nov.  15 

20 

23 
26 

Dec.     2 

5 

13 

17 
20 

25 
29 

1895 
Jan.     i 

3 

7 
15 

22 
26 
31 

Feb.    15 

21 

Mar.     i 
ii 
16 

7 
May  26 

July   24 

7 
7 

7 

7 
17 
16 
16 
16 

16 

16 
16 
16 
15 
15 
ii 

10 

6 

7 

7 
7 
6 

8 

6 
6 

7 
7 

7 

7 
7 

7 

7 
6 

7 
7 
7 
7 
7 
7 
7 
7 
14 

2410000+ 
2903.54 
2905-54 

2909.54 

2911-54 
2914.96 
2920.94 
2922.92 
2930.92 

2934-92  [ 

2943.92 
2946.92 
2951.92 
2956.88 
2973.88 
3010.71 

3039-67 
3148.50 

3I53.54 
3I56.54  { 
3159.54 
3165.50  -j 

3168.  58  -j 

3576.50 
3180.50 
3183.54 
3188.54 

3192-54 

3195.54 
3I97.54 

3201.54 

3209.54 
3216.50 
3220.54 
3225.54 
3240-54 
3246.54 
3254.54 
3264.54 
3269-54 
3270.54 
3310.83 

3399.63  • 

40 

40 
150 

40 

40 
150 
40 
40 
40 
40 
40 

40 

40 
40 
40 

40 

40 
40 

40 

40 
40 
40 
40 
40 
40 
40 
40 
40 
40 
40 
150 
40 

6 
6 

6 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

3 
6 

3 
(6 

b 
6 

3 
3 

I6 
(3 

J6 
(3 

11 

<6 

ia 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

64-501,  civ,  vi-2d  

34.5,  32.6,36.2  

9.27 
9.60 

8.97 

moon 
fair 

low 

o 

2 

6 

8 
ii 

i? 
'9 

27 

3i 
40 
43 
48 
53 
70 
107 

245 
250 

253 
256 
262 

265 

273 

277 
280 

3 

7 

10 

12 

16 

24 
31 

35 
40 

55 
61 
69 

79 
84 

85 
125 

214 

+  0.45 
+  0.74 

+  0.04 
+  0.17 

—  O.OI 

-0.13 

-0.37 
-0.52 
—  0.40 
—  0.60 
-0.30 

+  0.38 
+  0.18 

+  0.03 

+  O.O2 
—  O.O4 

+  0.03 

-0.17 

—  O.O7 
-0.13 
—  O.  10 

-0.38 
-0.23 

—  O.  12 

-0.25 

-0.36 

-0.34 
—  0.36 
-0.38 

-0.54 
—  O.2I 
-0.14 

-0.37 

fv  glimpsed,  62-3  n?...  \ 

v  not  seen,  trees,  etc  

twilight  too  bright  

c  and  d  seen,  D  uncertain 
di—  2D,  quite  certain  ..  . 

34 
33-2 
32.2 

31.8 
31.2 

31-4 
29.2 
29.2 

22.8 

•04 

<27 

35-1 
37-8 

39-2 
39-4 
39-7 

39-0 

39-4 

38.4 
38.5 
37-8 

38.9 

37-6 
36.4 
36.5 

35-4 
33-3 
32.5 
31-3 
28.4 
24.6 

22.2 
<26 

<25 
<26 

<i6 

27-7 

9-3 
9-47 
9-59 

9.64 

9-74 
9.70 

IO.O2 
IO.O2 
10.99 
12.3 
10.3 
9.18 
8.78 

8.58 

8-54 
8.50 

8.60 

8.52 
8.67 

8.66 
8.78 

8.62 

8.80 
8.98 

8.97 

9.12 
9-43 
9-55 
9.72 
10.15 
10.71 
11.07 

<  IO.O 

<io.6 
<io.s 

<  12.  0 

10.  24 

good 
fair 

low 

fair 
fair 
low 
fair 
fair 
fair 
fair 
fair 
good 

fine 
good 
good 

good 

good 

fine 
fair 
good 

good 

good 
good 

good 
good 
poor 
good 
good 
good 
poor 
good 
fair 
fair 

fair 

0*2—31;,  uncertain  

d2D,  c2-yv  
d3~  41;  

32.7,31-6  ( 
31.2  f 

dyv,  C4D,  vi-ie  
dyv,  Tio-ie  
en),  (ei—  21))  

31.7,  29.6,  32.2  
31-7,  31-2  

ds-6i',  £4-51),  ei-2i'  
e6i>,  D3&  
1}  not  held,  h  and  k  seen  . 

29.2,  29.1,  29.2  
24-7,  21.9  

v  not  held  limit  4  <  e 

&3D,  do-lV,  TJI-2C  

1)4^,  lib,  "V2d,  041)  

36.0,  34.2,  35.1  
37.6,39.0,36.7,38.0.. 

a2V,  v$d,  vib,   h2k  ) 
limit  2—  3<  k?                     i 

39-5,  38.7,  40.0  
39-0,  39-7,  41-0.  .  .]_ 
40.0,  39.5,  38.7.  .  .  > 
39-5,  38.2,  40.0.  .  .  I 
40.0,  36.7,  40.0.  .  .) 
39.0,  38.7,  40.5.  .  .) 
39.0,  38.7,  40.5.  .  .) 
38.5,  38.2  
39-o,  37-7,  38.5  
37-5,  38-2  

38.0,  37.7,  38.0  

38.0,  38.7,36.5.  .  .\ 
38.5,  37-5,  36.5  ••.) 
36-5,  37-2,  35-6  .  .) 
36.0,36.7  j 
37.0,36.7  1 
36.5,36.7  J 
36.0,  35.2,  35.1  

31-7,  33-6,  34-7  
32-2,  31.6,  33.7  

30.7,  30.1,  33-7,  3°-5 
28.2,28.5  
27-7,  23.5,  23.5,  23.9 
21.5,  22.9  

02—31),  Ti^d,  vib  
031),  v$d,  1)26  
vib,  02—31),  D4d  
02-31;,  D3-4d,  vib  
021;,  D2d,  DI&  
031),  i>4d,  i;i—  26  
03^,  1140",  1/1—26  

13-4".  ^3-4^,  (*3-4^?)  •  •  • 
031;,  vyi,  60-11;  
61-21;,  1/3-40"  

[•  611;,  1)30",  0411  
0411,  D4d,  62-31;  

03—41),  6  1—  2D,  V2(t  

05-61),  1)2-30",  62-311  
byj,  V2d  
621),  V2d  
62-31),  T>2d  
byv,  vo-id,  vi-2c  
dyv,  lie,  v^e  
d2-yv,  C2V,  1)36  
dAD  c  1—4.T    v\e.  v&l 

ei-yv,  V2l  

ew  Ivu  vim  wzh 

I^TI,  i>4/t  
D  not  seen  limit  /  

D  not  seen,  limit  i  </.  .  .  . 

i;  not  seen  limit  /  

v  not  seen,  limit  2—  3</i. 

v8h  

26.9..                   ..) 

eyv.  V2l   

27  7,  28.5  ) 

CHAPTER   II. — T   ANDROMEDA. 


21 


TABLE  n. — 103  T  ANDROMEDA.     VISUAL  OBSERVATIONS  OF  THE  VARIABLE — Continued. 


No. 

Date. 

Ocular. 

1 

£ 

I 

< 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing 

/. 

J  Mag. 

Month 
and  Day. 

Hour 
C.ST. 

Julian 
Day 
G.  M.  T. 

Steps. 

Mag. 

43 
44 

45 
46 

47 
48 

49 
50 
5i 

52 

53 

54 
55 
56 
57 
58 
59 
60 

61 
62 

63 
64 

65 
66 

67 
68 
69 
70 
7' 
72 
73 
74 
75 
76 
77 
78 

79 
80 

81 

82 
83 
84 

85 
86 

87 
88 
89 
90 

1895 
Aug.     5 

8 

12 

25 
26 
30 

Sept.    2 

9 
16 

17 
26 
Oct.      5 
9 
IS 
19 
23 
Nov.     i 

10 

Dec.     2 
9 
25 

1896 
Jan.     6 

13 
20 
Feb.     5 

8 

21 

Mar.     i 
3 

12 

Aug.     3 

27 
Sept.    7 

25 
Oct.      6 

24 
Nov.  26 
Dec.   23 

1897 
Jan.      6 
19 

28 

Feb.    13 

May   24 
July   21 

27 
Aug.  19 

27 

9 

8 

9 

8 
8 
8 

9 

8 
8 

7 

7 

7 
8 
8 
7 
7 
7 

7 

7 
6 

7 
7 

7 
7 
7 
7 
7 
7 
7 
7 
7 
10 

9 

8 

7 
7 
6 
8 
6 

6 

7 

7 

7 
'5 

10 

10 
9 
9 

2410000  + 
34"  -63 
3414.61 

3418.63 

3431-58 
3432.58 
3436-58 

3439.63 
3446.58 
3453-58 

3454-54 

3463-54 

3472  -  54 
3476.58 
3482.58 
3486.54 
3490.54 
3499-54 
3508  .  54 

35I3-54 
3530.50 
3537-54 
3553-54 

3565  •  54 
3572.54 
3579-54 
3595-54 
3598.54 
3611-54 
3620.54 
3622.56 
3631-54 
3775-67 
3799.63 
3810.58 
3828.54 

3839-54 
3857-52 
3890.58 
39I7-50 

3931-50 
3944-54 

3953-54  •} 

3969.54  ^ 

4069  .  88 
4127.67 
4133  67 
4156.63 
4164.63 

40 
40 

40 
40 
40 

40 
40 
40 

40 

40 

40 
40 
40 
40 
40 
40 

40 

40 
40 
40 
150 

150 
150 
150 
150 
15° 
150 
150 
40 

40 
150 
150 
15° 
150 
80 
150 
150 

150 
150 
40 
150 
150 
40 
150 
150 
150 
150 
150 

6 
6 

6 
(6 

b 

3 

I6 
(3 

3 
3 
6 

<3 
(6 

I6 
13 

6 
6 
6 
6 
6 
6 

6 

6 
6 
6 
6 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

d2v,  cyv  
•H4-5/,  civ,  Ti$e,  D2/,  di-2D  < 

32.7,  30.6  
31.0,  32.6,  35  7--1 

3i.fi 

32.8 

35-o 
38.8 

37-4 
39-0 

39-4 
38.2 

39-i 

38.7 

38.4 
40.4 
37-8 
35-6 
34-4 
35-i 
32.9 

3i-9 

30-4 
24.8 
22.3 
19.8 

15.8 
iS-i 
H-3 
n.  8 
ii.  8 
<i6 

<I2 

<i6 
<I9 
3i-4 
23.4 
22.4 
15-6 
16.6 
'3-3 

9-2 

11.9 

15-0 
18.6 

20.  i 

25.4 
23.2 
12.3 
10.4 
10.3 
10.4 

9.68 
9-51 
9.20 

8.63 
8.82 
8.60 

8-55 
8.72 

8.59 
8.63 

8.70 

8.38 
8.78 
9.  10 

9-27 
9.  18 
9-50 

9.63 

9  85 
10.68 
11.05 
ii  .42 

12.  OO 
12.  II 
12.  22 
I  2.  6O 
I  2.  60 
<  12.  0 
<I2.6 
<  12.  O 

<"   5 
9.70 
10.88 
11.03 
12.04 
11.88 

12.37 
12.97 

12.59 

12.12 
11.59 

"•37 
10.56 

10.91 
12.51 
12.80 

12.  8l 

12.80 

moon 
fair 

good 

good 
good 
good 

fair 
poor 
fair 

good 

fair 

fair 
good 
good 
good 
good 
fair 

good 

good 
moon 
good 
fair 

fair 
good 
moon 
fair 
good 
moon 
good 
good 
poor 
good 
good 
good 
good 
good 
good 
fine 
good 

good 
good 

good 

good 

good 
fair 
good 
fair 
good 

226 
229 

233 
246 
247 
251 

254 
261 
268 

269 

278 

5 
9 
15 
19 
23 
32 

4i 

46 
63 
70 
86 

98 

105 
112 
128 

131 

144 

153 
155 
164 
26 
50 

61 

79 
90 
1  08 
141 
168 

182 
195 
204 

220 

39 
97 
103 
126 

"34 

—  O.22 
—  O.26 

—  O.29 

—  O.  IO 
-f-O.  12 
+  O.OI 

+  0.01 

+  0.19 

—  O.OI 
+  O.O2 

—  O.O7 

-0.53 
—  O.22 
—  O.O9 
-0.03 

—  o.  29 
—  o.  29 

—0.50 

-0.48 
-0.30 

—  O.22 
-0.47 

—  0.36 
—  0.40 

-0-45 
—  O.2O 
—  O.  21 

+  0.15 
-0.40 
-0.13 
-O.62 

—  o.  19 

-0.32 
+  0.17 
+  0.13 

-O.O2 
+  0.06 

+  o  25 

+  0.31 

-0.84 
-O.2I 
+  0.32 
-O.OI 
—  O.OI 

32-5,  36.6,  35.7  .) 
35  o       ) 

04,  1/2,  vb,  D5d  

O3D  hiv  v^d 

38.0,  39.0,  39.  7.  .  » 
39.0,  38.0,  38.7..) 
37-5,  37-o,  37-7--  •• 
39-0,  39-7,  40.  5--  I 
38.0,  38.0,  39.2..) 
39-0,  39-5,  39-7--  •• 
39-0,  37-0,  38.7--  •  • 
39-5,  38-2,  39-5-  • 
39-0,  37-7,  38-0.) 
40.0,  38.7,  39.0.  .) 
38-5,  38-7   I 
39-0,  37-7,  38.0..) 
40.0,  40.7,  40.5..  .  . 
38.0,  37.7  
35-0,  35.2,  37.6..  .  . 
33-0,  34-7,  35-6..  .  . 
36-0,  34.7,  34.6..  .  . 
32-7,  32-6,  33.5..  .  . 
31.6,    32.7,   32.5,^ 
3°  9        •                  ) 

04—511,  62D,  i/3d  
ayv,  D5d,  7/1-26  
041;,  biv,  D4~sd  
ayv,  DO-i6,  Ti^d  
O3D,  621),  tiifd,  
02-31),  1)3-40",  DO—  1  6  
031),  1130",  6ii)  
0211,  1140",  1)6  
03—41),  1)40"  
031),  1)30",  611)  

O21),  1)6d,  DI—26  

611),  1)30"  
641),  Do-id,  D4C  
66i>,  i)d,  D2C  
6311,  lid,  DIC  

d2D,  CID,  1>4/  
C2T.  D2£.  D-*/.  D4.—  \l  .  .  .  -\ 

C3D,  DI—  2€,  D2/  
/21),  D4~  5W  
/5D,  D2TO,  D4/1  

30.6,  32.2,  28.5.  .  .  . 
24-5,  25.0  
21.5,  22.5,  22.9.  ... 

B-IOD,  DTO,  D2/I  
kyv,  DI-2&  

&4D,  DI&,  limit  3  <  k  ...  .  . 
•vk  

'7-5.  20.5,  20.2..  .  . 

15.9,  15-8  

14-9,  !5-3  

k2—yv,  limit  D  

k2—  31),  limit  D  

D  not  seen,  limit  3  <  h  .  . 

v  not  seen,  limit  2<fc  .  . 

D  not  seen,  limit  i—  2<h. 

D  not  seen  limit  h  .  .  . 

^4-5',  dye  

'3",  «^-5*  
lyv,  1)4—  sA  

A3D,  1>l£  
&2D,  D2ife  

&ID,  limit  i—  2<D  ,  .  . 

31-0,  3i-7   
23-5,  23.4  
21.5,  23  4  
15-9,   '5-3  
16.9,  16.3  

£51),  III)  
&2D  DI—  2X 

93,  9-0  
12  i   ii    =; 

&5-6D,  DI-2*  

AO-ID,  1)4—  5&  

13-4,  15-8  
18  4    18  8 

D&,  /4D  
DO-lA,  l(t-SV  
ZlD,  TtSk  
/2D  

18.9,  22.5  \ 
19  4,  19-5  / 
25-5,  26.9  ) 

24.    ^                                    1 

/5i>  vfth 

k2V,  limit  v  

k^TI,  TO-  IX  

&4D,  limit  D  

JO-3,   10.5    

k$v,  vo-ix  

10.3,  10.5  

22 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABLE  n. — 103  T  ANDROMEDA.    VISUAL  OBSERVATIONS  OF  THE  VARIABLE — Continued. 


No. 

Date. 

1 

O 

I 

& 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing. 

' 

d  Mag. 

Month 
and  Day. 

Hour 
C.S.T. 

Julian 
Day 
G.  M.  T. 

Steps. 

Mag. 

92 
93 
94 
95 

96 

97 

98 
99 

IOO 
101 
IO2 

103 
104 
105 

106 

107 

108 
109 

IIO 

III 

112 

"3 

114 

"5 

116 

118 
119 
1  20 

121 
122 
123 
124 

125 
126 
127 
128 
129 
130 

132 
133 
134 
135 
136 

'37 
138 
139 

1897 
Sept.  16 
20 

24 
29 
Oct.    14 

23 
25 

29 
Nov.  n 

17 
20 
Dec.   29 

1898 
Jan.    i  6 

23 
Feb.      5 

24 
Mar.     4 

'3 
Aug.  29 
Sept.    8 
Oct.    1  1 

Nov.     5 

19 
Dec.     3 

22 
1899 

Jan.      2 
9 
24 
Feb.   15 
28 
Mar.     7 
Aug.  10 
18 
Sept.    i 

13 
Oct.      2 

7 
23 
30 
Nov.     4 
20 

27 
Dec.     6 

19 
23 
29 

1900 
Jan.      i 

22 

24 

7 
8 
8 
8 
7 

7 
6 

7 

7 
7 
7 
7 

6 

7 
7 
7 
7 
8 
8 

7 
6 

7 
6 

6 
6 
6 
6 

8 
7 
9 
8 
8 

7 
8 

7 
7 
7  ' 

7 
7 
7 
7 
7 
7 
7 

6 

7 
7 

2410000+ 
4184.54 
4188.58 
4192.58 
4197-58 
4212.54 

4221.54  \ 
4223.  50  -s 

4227-54  I 
4240.54 
4246.54 

4288.54 

4306.54 
4313.50 
4326.54 
4345-54 
4353-54 
4362.54 
4531.58 
454I-58 
4574-54 
4599-50 

46I3-54 
4627.54 
4646  .  50 

4657  •  50 
4664.5 

4679.5 
470i  .  5 
47I4-58 
4721-54 
4877-63 
4885.58 
4899.58 
4911.56 
4930.58 
4935  •  54 
4951.54 
4958  -  56 
4963-56 

4979-54 
4986.54 

4995  •  54 
5008.54 
5012.54 
5018.52 

5021.50 
5042  .  54 
5044.54 

150 
150 
150 
150 
150 
40 
15° 
15° 
80 
80 
40 
150 
40 
40 
40 
40 

40 
40 

150 
40 
150 
40 
40 
80 
40 
40 
40 
15° 

150 
150 
150 
150 
150 
150 
40 
40 
40 
40 
40 
40 
150 
150 
150 
150 
200 
150 
200 
200 
200 

200 
150 
150 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

6 
6 
6 

£4—  51*,  ac  not  seen  

9-8 
13.2 
14.4 
16.1 
16.8 

17.0 
18.8 

19.6 

23.7 
27.6 
28.3 
41.2 

39-2 
37-o 
32.1 
30.1 
25.0 
22.5 
25-8 

27.  2 
39-4 
37-8 
S3-2 
27.6 
23.0 

21  .  I 
19.2 
14.4 
10.3 

9-8 

38.2 
36-6 

34-4 
31.8 
26.2 
24.0 
19.9 
16.6 
15.6 

12.6 
II  .2 
II  .  2 

"•3 
IO.2 

10.  ± 

,    9'8 
II.9 

12.90 
12.38 

1  2.  2O 
11.97 

11.85 

11.80 
11.56 

"•45 

10.84 
IO.27 

10.  17 

8.28 

8-57 
8.90 
9.60 
9.89 
10.63 
1  1.  02 
10.52 
10.31 

8.54 
8.78 

9-47 
10.27 
10.94 

n  .20 
11.50 

12.  2O 
I2.8I 
12.89 

<n.8 
8.72 
8.98 
9.27 
9.64 
10.47 
10.63 
n  .40 
11.88 
12.03 
12.48 
12.69 
12.69 
12.67 
12.82 
12.86 

12.89 

<I2.9 

12.59 

fair 
good 
good 
good 
good 

good 
good 

good 

good 
good 
good 
good 

good 
good 
fair 
fair 
fair 
fair 
moon 
fair 
good 
good 
good 
good 
good 

poor 
fair 
moon 
moon 
low 

fair 
moon 
fair 
good 
good 
good 
good 
good 
fair 
poor 
good 
good 
fair 
fair 

good 
poor 
good 

153 
'57 
161 
1  66 

181 

190 
191 

196 

209 

215 

218 

257 

275 
o 

13 
32 
40 

49 
218 
228 
261 

4 
18 
32 
51 

62 
69 
84 
1  06 
119 
126 
o 
8 

22 

34 
53 
58 

74 
81 
86 

102 
IO9 

118 
131 
135 
141 

144 
165 
167 

+  O.  22 
-0.27 
-0.38 
-0.52 

—  o.  29 

+  0.03 

—  o.  14 

—  0.04 
—  0.04 

-0.27 

—  o.  20 

—  o.  24 

-0.13 

+0.08 
+0.48 

+  0.  II 

+0.53 

+  0.60 
+  o.  15 

+0.51 

+  O.OI 
—  O.  II 

+  o.  19 

+0.47 
+0.42 

+0.25 
+0.30 

+0.43 
+0.28 
+  0.16 

—  O.OI 
—  O.O2 

-0.13 

—  0.23 
—  0.15 
-0.18 
o.oo 
+0.19 
+0.13 
+0.03 
+0.09 
—  0.04 
—  o.  14 

+  O.OI 

+  0.06 
+  0.09 

+  O.  II 

&2K,  1)4*,  limit  x  
kiv  v$x,  h^v 

12.3,  14.0  
13.3,  15.0,  14.9..  .  . 

16.3-  15.9  
16.3,  17.4  

V2k,  hyv  

V2k,  hi—  2V  

16.9,  16.  3  .  .  .  ) 

hi—  2V,   V^k  

ho—  iv  v$k                       ") 

17-4,  17-3  i 
18.4,  19  3  

hin,  mo,  oip,  piq,  qk.  ';- 
k\r,  k2t,  Is  ) 

17-9,  20.3  ) 
20.5,   19.9  ) 
22.9,  24.5  
26.5,  29.7  
28  .  o,  28  7  

hiv,  v6k  

v^h,  hv  
vl,  d6v  
vi—  2/  d6v 

V2b,  ao—iv  

ayv,  vo-ib,  046  

6O-IT,     V2d,    V&l  

39-0,  39-5  
38-5,  36-7,  34-5  -  - 
32-7,  3i-5  
30-7,  29.5  

d^v,  v$l  

/I—  21? 

IdV 

hv,  vis,  uncertain  

vl   c$v 

25.5,  26.1  
26  5  28  6 

03—41),  v^d,  1/26  
61—  2V,  1)3—  4<i  
64—51?,  i?3/,  do-in,  TIC... 

38.5,  38.7,  41.0  .. 
37-5,  38.2  
34-5,  29.5,  34.2,  34.6 

2Q  7.  2S  S  . 

;P_'          fr 

22.  0,  23.9  

ly>,  vih  

23-5,  '9-9  
19-5,  17.3,  20.9  .  . 
l6  4.  12  T, 

£41?    limit  i?  

£4—  51?    limit  v      .  . 

v  not  seen,  limit  1-2  <  h  . 
a^v   vb   v$d  

38.0,  39.0,  37.7.  . 
36.5,  36.7  

35-0,  33-7,  34-6.  .. 
30.7,  34.1,  30.5.  .  . 
28.1,  26.5,  23.9  .  . 
24-5,  23.4  
20.5,  20.9,  18.3  .  . 
16  4,  16  8  . 

62-31?,  V2d  
6411,  div,  vie  
dq.v,     vo-ic,  i?4/  
05-61?,  vl,  v$h  

/2D,    1)4—5/1   

/6f,  i?2^,  i?4&  

h2v,  vk,  x  not  held  .... 

klV,    V2X   

kyv,  vix  

16.9,  14.3  
13-3,  12.0  
11.3,  n.  o  
11.3,  11.  o  

£41?    vx    limit  v  or  x  .... 

10.  3,  10.0  

xo—iv   limit  v  

£51?,  DO-I*  
v  not  seen  limit  k  

9-3,  10.3  

631?,  D2-3*,  limit  x  

II-  3,  12-5  

CHAPTER  II. — T   ANDROMEDA. 


TABLE  n. — 103  T  ANDROMEDA.     VISUAL  OBSERVATIONS  OP  THE  VARIABLE — Continued. 


No. 

Date. 

Ocular. 

tj 

I 

Comparisons. 

x 
Reduction,  Steps, 

Means. 

t. 

J  Mag. 

Month 
and  Day 

Hom- 
CS.  T 

Julian 
Day 
G.  M.  T. 

Steps. 

Mag. 

Seeing 

140 
141 
142 
143 
144 
145 
146 

147 
148 
149 
150 
151 

152 

i53 
154 
155 
156 

157 
158 
i59 
1  60 
161 
162 
163 
164 

165 
1  66 
167 

168 
169 
170 
171 
172 
173 
174 
175 
176 
177 
178 
179 
1  80 

1900 
Feb.   15 
26 
May   20 
June  25 
July  30 
Aug.  26 
Sept.  15 
Oct.    10 
18 
Nov.  21 
Dec.    n 
29 

1901 
Feb.     9 

1903 
Feb.    1  6 

24 
Oct.    1  1 

13 

1904 
Aug.  29 
Sept.  ii 
Oct.     6 
27 
30 
30 
3i 
Nov.     i 

2 

'4 
29 

1905 

Jan.    14 
28 
Feb.   25 
Mar.     3 
May   22 
June  10 

27 
July   30 
Aug.     9 
28 
Sept.  17 

Oct.     20 

Nov.  21 

7 
7 
14 
14 
10 
8 
7 
7 
1  1 

7 
7 
6 

9 

8 
8 

8 
10 

8 
6 
6 

6 

7 

6 

9 

8 

7 
7 
15 
15 
15 

12 
14 

9 

8 
8 
6 

2410000  + 
5066.54 

5077.54 
5160.83 
5196.83 
5231-67 
5258-58 
5278.54 
5303  •  54 
53ii-7i 
5345-54 
5365-54 
5383-50 

5425-63 

6162. 
6170.58 
6399-58 
6401  . 

6722.58 
6735  67 
6760. 
6781.58 
6784.50 
6784.50 

6785-54 
6786.50 

6787.54 
6799. 
6814.50 

6860.63 
6874.58 
6902  .  54 
6908  .  54 
6988.88 
7007  .  88 
7024.88 

7057-75 
7067.83 
7086.63 
7106.58 
7I39-58 
7I7I-50 

150 
150 
40 
40 
40 
150 
150 
150 
237 
15° 
40 

40 

40 

'67 

150 

6 
6 
6 
6 
6 
6 
6 
6 
40 
6 
6 
6 

6 

24 
12 
6 

h2TJ,    112k    

16  .  o.   16  "}  .  . 

16.6 

19-  ± 
37-6 
29.8 

22.2 
12.3 

9-± 
<I3 

II  .  2 
17.2 

23-4 
26.5 

39-3 

11.89 

ii  5 

8.80 

9-94 
ii  .07 
12.52 
13.0 

<I2.4 

12.67 
11.79 
10.88 
10.42 

8-57 

IS-  2± 
I3.I7 
12.  8l 

fair 
poor 
fair 
good 
good 
fair 
good 
moon 
fair 
good 
good 
good 

fair 

good 
good 

189 

200 

2 
38 
72 

99 
119 

144 
152 
1  86 
206 
224 

266 

157 
165 
112 

+  0.06 

+  0.2 
—  O.O7 
+  0.08 
—  0.30 
+  0.15 
+  0.27 

-0.03 

—  o.  14 

-0.13 
+0.39 

—  O.O2 

+  0.67 
+  0.04 

vh± 

bin,  112—  ^d  

Cl—  2V,    Till  

l$v,  114/1  
k2i>,  limit  v 

38.0,  37.2  
32.1,  27.5  
21.5,  22.9  

v  glimpsed,  k$v  .         * 

11  not  seen,  limit  l<.k 

k^ll,    TJ2X  
tl2T),    T2k,  16—811 

10.3,  12.0  
16.9,  16.3,  19.5  . 
2^  .  5.  2T.  3  .  . 

/3f,  i>8—  lok  

•vl  

bv,  V4-5<f,  Tide  

39-o,  39-2,  39.6  .. 

photograph  

X2V  ,  limit  v  

8.0 
10.3 

k^v,  limit  1}  .  . 

150 

67 

40 
40 

460 

67 
67 
67 

40 

237 
237 
237 

67 

250 
237 
237 
237 
150 
150 
150 

80 
150 

6 
12 
6 
6 
6 
40 
12 
12 
12 
12 
6 

40 
40 
40 
12 
40 
40 
40 
40 

6 
6 
6 

12 

6 

v  not  seen,  limit  6  <  h  .  . 

<I3 

<   7-0 
<  10 

13-4 
13-6 
13  6 

<I2.4 

<i3-3 

<I2.9 

12.36 
12.34 
12.34 
11.89 

I  2.  O2 
11.84 

ii.  3± 
i°-45 

8.42 
8.58 
9.69 

IO.  I  I 

12.70 
13.18 
12.86 
11.87 
ii  .  14 
ii  .04 
9.68 

8.12 

8.70 

poor 
good 
good 
fine 

good 

good 
good 
fair 

fair 

fair 
good 
good 
fair 
moon 
fair 
fair 
good 
good 
fair 
poor 
good 
good 

153 
1  66 
191 
212 

215 
216 
216 

217 
230 
245 

9 
23 
51 
57 
137 
156 
173 
206 
216 
235 
255 
6 
38    - 

+  i-'65 
+  1.78 
-i  .40 
+  1.53 
+  1.38 

+  ^87 

-0.58 
-0.85 
-0.82 

-0.59 
-0.08 
•(-0.51 

fO.52 

f  0.86 
fo.65 
f  1.64 

fi.15 
-0.78 

-1.3° 

11  not  seen,  limit  3  <  x  .  .  . 

11  not  seen,  limit  x  

ko-m,  1131  
nk,  vyc  
kv,  V3X  
photometer  

13.8,  13.0  
14-3,  '3-o  
14-3,  13-0  

photometer  

photometer  

photographs  

photometer  

photometer  

photometer  

photometer  

e$ii,  113-41  

kSv     V2X   

25-7!  30.0  

6.3,  12  O  ... 

27.9 
10.9 

IO.O 

16.3 

21.6 
22.2 

31-4 
42.O 
38.2 

9.0,  (13.15,  13.38). 
IO  O 

112k                .            

18—iov    i>6k,  u^h  

(15.5),  20.3,  22.9 

22.3,  19-3,  23.5,  21.5 
29.2,  33-7  

v$k    vjt    V3m    l$i> 

ei-2V,  dm  
Da             

af>i>,  bv,  v^d  

36.0,  39.0,  38.7  .. 

24  RESEARCHES  IN  STELLAR  PHOTOMETRY. 

The  whole  time  covered  by  the  observations,  starting  from  the  first,  was  divided 
into  parts  corresponding  in  length  with  the  star's  assumed  period.  The  quantity 
t  in  the  twelfth  column  is  the  time  elapsed  in  days  since  the  beginning  of  each 
of  these  parts.  The  last  column,  "  j:Mag,"  gives  the  residual  between  the  ob- 
served magnitude  and  the  reading  from  the  mean  light-curve  corresponding  to 
the  time  t. 

Table  12  gives  the  data  for  finding  the  mean  light -curve,  following  the  form 
used  by  Turner  in  his  reductions  of  the  Rousdon  variable  star  observations' 
with  some  additions.  Dividing  the  assumed  period,  282  days,  into  twelve  parts 
we  have  in  this  case  23.5  day  groups.  The  heading  of  Table  12  gives  in  two 
lines  the  number  of  the  group  and  the  day  number  corresponding  to  the  last 


MAGNITUDE 


T  ANDFtOMEDAE 


FIG.  4. — MAGNITUDE-CURVE  FOR  T  ANDROMEDA. 

day  of  the  group.  The  first  column  gives  the  Julian  day  of  the  beginning  of 
each  period,  starting  from  an  arbitrary  date,  the  first  observation.  Then  follow 
for  each  group  of  each  period,  the  mean  t  and  magnitude  in  the  Harvard  system 
(found  by  averaging  the  quantities  in  the  last  two  columns  of  Table  1 1  for  the 
interval  covered  by  the  group)  J  M,  the  difference  between  the  mean  magnitude 
and  the  reading  from  the  mean  light-curve  for  the  time  t,  and  the  number  of 
nights '  observations  in  the  group.  Finally,  at  the  foot  of  the  table  will  be  found 
the  general  means  of  the  tabulated  quantities  t,  M  and  4  M,  followed  by  the 
total  number  of  observations  in  each  group.  These  general  means  of  t  and  M  are 
platted  to  form  the  mean  light-curve  (fig.  6,  page  27). 


'  Memoirs  of  the  Royal  Astronomical  Society,  vol.  55,  lix  et  seq. 


CHAPTER   II. — T   ANDROMEDA. 


a,  si, 
00  o 

~  <0 


•o 

<n  <5 
co  o 

~ 


r 


^_ 


o 
m 


§ 


00 
en  f> 


I 

Z    § 

K     i 


s§ 


o  5; 

CO  •" 


FlG.    5. — LlGHT-CURVB  OF   T    ANOROMKU.'li. 


26 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABLE  12.— MBAN  MAGNITUDES  PROM  23.5  DAY  GROUPS. 


Group  No.  .  .  . 
T    D 

i 

27     S 

2 

47 

3 
70.5 

4 
94 

5 
117.5 

6 

141 

7 
164.5 

8 
1  88 

9 

211.5 

IO 

235 

II 

258.5 

12 
282 

r      / 

251 

274 

M 

8.77 

8.61 

29°3         JM 

—  o  ^o 

+  0.15 

—  0.08 

L     No 

4 

4 

r      t 

62 

223 

250 

269 

M 

8  88 

9.66 

8.65 

8.66 

3I85  \      JM 

o   18 

—  0.28 

+  O.OI 

+  0.03 

L    No 

•i 

4 

4 

4 

I/ 

if) 

66 

86 

* 

M 

8  88 

10  86 

JM 

Nn 

i 

3749  ]     £ 
I     No. 

I        M 

26 
9.70 
+  0.15 
I 

39 

IO    QI 

56 
10.96 
+  0.26 

2 

84 
11.96 

+  O.22 
2 

108 

12.  27 
—  O.22 

I 

IOO 

12  86 

141 
12.97 
+  0.17 

i 

130 

12     3O 

157 

12    52 

175 
12.36 
+  0.08 

i 

i74 
11.91 

200 
11.48 
+  0.16 

2 

196 
II  .41 

220 
10.56 
+  0.31 
i 

216 

IO.22 

257 
8.28 

275 
8.57 

4031  1      ,rj 
JM 

I    No. 

r      , 

6 

+  0.84 
i 

•?6 

4.O 

+  0.26 

2 

O.OO 
2 

—  O.  12 
3 

—  o  42 

2 

—  0.05 

4 

—  O.24 

2 

2.  23 

—  0.24 

i 

-0.13 
i 

261 

O    2^ 

10  26 

1  1  .  02 

10.42 

8-54 

JM 

f-o  28 

+  032 

+  o  60 

+  0.33 

+  O.OI 

L    No 

2 

I 

2 

i 

r     * 

61 

84 

12    28 

12    8l 

12    89 

4595         JM 

-\-  O    "\2 

4-O    A'l 

+  o  28 

+  o   16 

L      Mn 

r     / 

c6 

8O 

106 

128 

167 

IQA 

A&77     ;'             M 

8  98 

12      C8 

12  88 

12     =10 

1  1     7O 

JM 

_j_  o  05 

+  o  08 

-f-o  16 

+  O    I  ^ 

L    No 

i 

2 

f     ' 

5159  J        M 
I      JM 
L    No. 

r     t 

2 
8.80 
—  O.O7 
I 

38 

9-94 
—  0.08 
i 

72 

n  .07 

-0.30 

I 

99 
12.52 
-4-0.  15 
I 

119 

13    0± 

+  0.27 

I 

••52 
12.67 
—0.03 
i 

1  86 
11.79 
-0.17 
i 

165 

2O6 

10.88 
-0.13 

i 

224 
10.42 
+  0.39 
I 

266 

8.57 

—  O.O2 
I 

T  -3     17 

JM 

+  o  67 

L    No 

i 

r         / 

6287  J        M 

12    8l 

]      JM 

L    No 

r       / 

6851  J        M 

1      JM 

L     No 

•  r     t 

Means  j     '    M 
1      JM 
L     No. 

9 
8.97 

+  O.O2 
2O 

34 
9-93 
+  0.05 

19 

57 
10.75 
o.oo 

15 

79 
"•57 
—  0.03 

9 

105 

12.55 

+  O.O2 
II 

128 
12.84 
+  0.05 

IO 

150 

12.69 

+  O.OI 

6 

'73 
12.36 
—0.09 
6 

199 

"•37 
+  0.03 

9 

2  2O 
IO.22 
+  O.IO 
IO 

253 

8-57 
—0.03 

9 

268 
8.60 
—  0.04 
II 

CHAPTER   II. — T   ANDROMEDA. 


too 


DAYS 

zoo 


300 


4-00 


ANDROMCDAE 

M  «.     ^S8ef 
m  =     /32 
M-m-  /26 


COMPLETE   LIGHT-CURVE. 
(Fig-  5,  page  25.) 

This  is  formed  by  platting  the  magnitudes  (in  the  Harvard  system)  from  Table 
1 1 ,  and  indicating  the  limit  of  visibility  when  the  variable  was  not  seen  by  the 
point  of  the  V-shaped  character.  A  smooth  curve  drawn  through  the  platted 
points  shows  the  light  changes  of  the  variable.  When  the  number  of  observations 
is  insufficient  to  give  an  accurate 
curve,  it  is  drawn  with  a  broken 
line  by  the  aid  of  the  mean  curve. 
The  dates  and  magnitudes  of  max- 
ima and  minima  given  in  Table  13 
are  taken  from  this  light -curve.  The 
correction  to  the  ephemeris,  given 
in  the  sixth  column,  is  calculated 
from  the  elements  at  the  head  of 
the  table,  with  the  corrected  period 
284  days.  The  weight  in  the  sev- 
enth column  results  from  the  num- 
ber of  observations  combined  with 
their  symmetry  with  respect  to  the 
maximum  or  minimum.  In  case  of 
a  symmetrical  distribution  the 
weight  is  f  times  the  number.  If 
the  observations  all  lie  on  one  side 
the  weight  is  \  the  number.  In 
case  the  date  of  maximum  or  mini- 
mum depends  on  the  mean  curve, 
the  letters  "me"  are  placed  in  the 
magnitude  column. 

TABLE  13. — 103  T  ANDROMEDA. 
Elements  of  maximum. 


LJ 
O 

D 
h 

O 


/2 


I3 


FIG.  6. — MEAN  LIGHT-CURVE  OF  T  ANDROMEDA. 


OBSERVED  MAXIMA  AND  MINIMA. 

1894  Nov.  28  (J.  D.  2413161) +  284<>X(E-S1)- 


M-m=1264 


MAXIMA. 

MINIMA. 

i 

Date. 

Mag. 

| 

Date. 

Mag. 

Wt 

a 

H 

Calendar. 

J.  D. 

H. 

P. 

Lorr. 

| 

W 

Calendar. 

J.  D. 

H. 

P. 

50 

1894  Mar.     2 

2890 

me 

+  13 

6 

5» 

1894  July  26 

3036 

me 

+    i 

2 

51 

Dec.     3 

V66 

8  49 

8.S7 

+    5 

24 

52 

1895  May    6 

3320 

me 

+    i 

7 

52 
53 

54 

1895  Sept.  9 
1896  June  13 
1897  Mar.  21 

3446 
3724 
4005 

8.58 

8.66 
me 
me 

+    i 

-    5 

-    8 

28 

2 

3 

53 
54 
55 

1896  Feb.  14 
1896  Nov.  24 
1897  Aug.  1  6 

3604 
3888 
4'53 

me 
12.98 
12.90 

+    i 
+    i 
-18 

6 
15 
i? 

12.90 
12.82 

55 

Dec.  31 

4290 

8.3° 

8.38 

—    7 

13 

56 

1898  June    3 

4444 

me 

—  ii 

i 

56 

1898  Oct.  18  .  4581 

8.32 

8.40 

o 

10 

57 

1899  Mar.  it 

4725 

12.9 

13-0 

-  '4 

4 

57 
58 
59 

1899  July  22 
1900  Apr.  29 
1901  Feb.    2 

4858 
5139 
5417 

me 
8.6 
me 

-    7 
—  10 
-16 

4 
7 

2 

58 

59 
62 

Dec.  25 
1900  Sept.  28 
1903  Feb.  14 

5014 
5291 
6160 

12.90 
13.00 
13.2 

12.98 
13.08 
13.3 

-   9 
-16 

+    i 

20 
IO 

I 

64 

1905  Jan.  14 

6860 

me 

+    7 

2 

64 

1904  Sept.   6 

6730 

me 

+    3 

5 

28 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABLE  14.—  PHOTOMETRIC  MEASURES  AND  COLOR  OF  COMPARISON  STARS. 


Star. 

H.  C.  O. 
37,i5i 

Lindemann 
+  0.18 
A.  N.  139,345 

H.  M. 
Parkhurst 
A.  J.  15,77 

J.  A.  Parkhurst. 

Yendell, 
Visual 
A.  J.  15,93 

Color, 
Plates 
1  49  and  150 

Hagen. 

H. 

P. 

a 
6 
c 
d 
e 
I 
s 
t 
k 
y 
•v 

8.08 
8.45 

8.03 
8  80 

9  29 

8.5' 
8.76 

9.26 

7.98 
8.72 

9  5i 
9.12 

IO.20 
10.15 
10.32 

11.66 
11.85 
13.12 

8.06 

8.80 

9  59 
9.  20 
10.28 
10.23 
10.40 
11.74 

"  93 
13.20 

8.18 
8.  10 
9.07 
8.58 
9.60 

10.  2O 

+  0.37 

—  O.O2 
—  0.03 
+  0.  II 
—  0.08 
+  O.  I  I 
+  0.  IO 

+  0.08 
—  0.09 

+  0.52 

8.1 

8.5 
9.0 
8.8 
9-7 
9-9 

IO.O 

12.4 
12.5 

9.01 

10.62 

12-34 
12.50 

13.89 

12.55 

Table  14  collects  the  other  photometric  measures  of  these  comparison  stars 
which  are  known  to  the  writer,  adding  Hagen 's  and  Yendell 's  visual  scales  and 
the  measure  of  the  color  from  a  comparison  of  photographs  taken  on  ordinary 
and  isochromatic  plates.  The  Harvard  results  in  the  second  column  reveal  a 
considerable  difference  in  scale,  but  reference  to  the  volume  cited  shows  that 
the  measures  of  the  four  faint  stars  depend  on  the  single  star  d,  which  seems  too 
narrow  a  foundation.  Again,  before  any  larger  aperture  had  been  used  on  the 
field,  the  writer  selected  the  comparison  star  x  with  the  6-inch  reflector,  whose 
limit  of  vision,  as  determined  by  all  the  photometer  measures,  lies  between  12.8 
and  13.0.  If  this  is  true  the  Harvard  values  for  the  faint  stars  are  numerically 
too  large  by  at  least  three-quarters  of  a  magnitude. 

I/indemann's  results  were  based  on  the  magnitude  6.50  for  the  star  B.  D. 
+  26°23  (P.  DM.  6.68)  and  are  therefore  increased  byo.iSto  bring  them  to  the 
Potsdam  system.  They  show  a  very  close  agreement  with  my  values  in  column  P. 

H.  M.  Parkhurst 's  measures  make  the  yellow  star  a  about  half  a  magnitude 
fainter  than  the  other  values.  The  Purkinje  phenomenon  would  seem  to  explain 
the  difference,  as  he  used  an  extinction  photometer,  while  the  others  used  the 
full  light  of  the  star.  A  difference  in  scale  is  also  indicated  by  the  single  faint 
star  k,  but  this  is  entitled  to  a  relatively  small  weight  as  it  depends  on  only  two 
double  extinctions,  while  the  other  stars  have  six  to  nine;  and  in  other  fields  our 
scales  are  in  good  agreement. 

The  writer's  results  are  given  in  columns  H  and  P  on  both  the  Harvard  and 
Potsdam  scales. 

Yendell 's  visual  scale  is  added  for  comparison.  The  color  of  the  star  a  probably 
accounts  for  his  estimating  it  with  a  4. 2 5 -inch  aperture  fainter  than  the  star  b. 

The  "Color"  column  gives  the  difference :  Magnitude  on  ordinary  plate  minus 
magnitude  on  isochromatic  plate.  It  will  be  noticed  that  these  differences  are 
within  the  combined  accidental  errors  of  the  visual  and  photographic  measures, 
except  for  the  stars  a  and  v.  At  the  present  writing  the  data  are  insufficient  for 
expressing  these  color  numbers  on  the  usual  decimal  scale,  but  an  idea  of  their 


CHAPTER   II. —  T   ANDROMEDA.  29 

relation  can  be  had  from  the  coloration  of  the  variable  given  by  Yendell,  5.2,  and 
by  the  Gesellschaft  Committee  on  Variables,  6.0. 

Besides  that  here  given,  three  light-curves  have  been  published  for  the  variable 
near  maximum.  The  curve  first  published  by  Pickering  inAstrophysical  Journal, 
1,  305,  1895,  was  anomalous  in  character,  consisting  of  two  straight  lines  meeting 
at  the  point  of  maximum.  This  curve  has  unfortunately  gained  some  publicity 
and  been  widely  quoted,  but  seems  to  lack  confirmation.  Pickering's  second  curve 
'n  the  same  journal,  3,  281,  is  of  a  different  character  and  agrees  with  that  given 
by  Yendell  in  Astronomical  Journal,  15,93,  also  with  the  curve  here  given.  As 
far  as  known,  no  other  complete  light-curve  has  been  published,  as  observations 
near  minimum  have  been  scarce.  Those  published  by  H.  M.  Parkhurst  in  the 
Astronomical  Journal,  vols.  15  and  17,  for  epochs  53  and  54,  number  9  and  8, 
respectively.  In  Harvard  Annals,  37,  206,  the  minimum  of  epoch  38  was  observed 
by  Reed,  who  gives  seven  observations  when  the  variable  was  fainter  than  the 
eleventh  magnitude. 

The  period  284  days  satisfies  the  present  set  of  observations  better  than  the 
shorter  period  281  days  given  by  Chandler,  Pickering,  and  the  Gesellschaft  com- 
mittee, and  demanded  by  the  B.  D.  observations  of  1855.  Hagen  gives  in  the 
catalogue  sheet  to  the  "Atlas"  the  elements  of  maximum: 

1891  December  14  (2081)  -j-  274  E. 

This  period  is  so  much  too  short  that  the  calculated  maximum  1 7  falls  at  Julian 
day  6739,  only  nine  days  after  the  observed  minimum. 

We  conclude  that  at  present  the  period  is  lengthening. 


CHAPTER  III. 

267  V  ANDROMEDA. 
R.  A.  oh  44™  39.7*  ;  Dec.   +35°  6'  30"  (1900). 

The  announcement  of  the  discovery  of  this  variable  by  Anderson  was  received 
in  the  Astronomische  Nachrichten,  142,  159,  in  January,  1897.  Observations 
began  at  once  and  the  definitive  notation  was  published  by  Chandler  in  Astronom- 
ical Journal,  If,  87,  February,  1897.  Some  confusion  arose  from  an  apparent  con- 
tradiction between  the  observations  of  Yendell  and  the  writer  (noted  by  Hartwig 
in  the  Vierteljahrsschrift,  32,  187),  occasioned  by  a  misidentification  explained 
in  Astronomical  Journal,  8  ,  62.  Some  trouble  may  also  arise  from  the  fact  that 
the  Chandler  number  of  the  star  is  given  as  268  in  the  Nachrichten,  160,  335,  and 
in  the  Harvard  Provisional  Catalogue  of  Variables,  Annals, 48,  96,  whereas  that 
number  was  assigned  by  Chandler  to  X  Sculptoris  in  the  Journal,  17,  88. 

As  Hartwig 's  observations  of  the  star  are  not  yet  published,  there  are  only 
available  for  comparison  three  isolated  observations  by  Esch  in  the  Nachrichten, 
160,  335,thestar  being  found  invisible  in  February,  1902  (then  13™  by  my  curve) 
and  9.3™,  1902  August  22. 

The  positions  of  the  variable  (relative  to  the  star  a,  in  Leyden  A.  G.  Cat.) 
and  the  brighter  comparison  stars  were  measured  with  the  6-inch,  the  fainter 
stars  with  the  4o-inch,  and  all  positions  were  checked  from  the  photograph. 

The  three  fundamental  magnitude  stars  (Table  15)  are  white,  which  perhaps 
accounts  for  the  small  residuals  and  the  close  agreement  of  the  results  with  the 
Potsdam  values. 

The  mean  light-curve  was  formed  from  the  observations  up  to  February,  1905. 
It  bears  a  close  resemblance  to  that  of  T  Andromedae,  the  only  difference  being 
the  length  of  the  period.  No  halting  in  the  regular  change  has  been  observed, 
but  there  is  a  range  of  more  than  a  magnitude  in  the  brightness  at  different  max- 
ima and  half  a  magnitude  at  the  minima.  A  pair  of  ordinary  and  isochromatic 
plates  taken  1904  November  15,  showed  no  color  difference  between  the  variable 
and  the  comparison  stars  d,  e,  and  m. 

The  revised  elements  given  by  Chandler  in  Astronomical  Journal,  ]Q,  94, 

Max.=i896  Nov.  5  (3869) +  263  E 

as  well  as  Hartwig's  ephemeris  in  Vierteljahrsschrift,  39,  262,  call  for  a  maximum 
epoch  12,  1905  June  28.  The  observed  date,  May  5,  though  dependent  on  a 
small  number  of  observations,  does  not  seem  liable  to  an  error  greater  than  10 
days,  so  that  the  Chandler  period  is  evidently  too  long.  The  present  set  of 
observations  are  best  satisfied  by  a  period  of  259  days,  as  given  at  the  head  of 
Table  23. 


3J 


RESEARCHES  IN  STELLAR  PHOTOMETRY. 


TABLE  15.— STANDARD  MAGNITUDE  .STARS. 


1900. 

Magnitude. 

Residuals. 

Star. 

B.  D.  No. 

RA 

Color. 
P.  DM. 

Catalogue. 

Measured. 

From  Cats. 

3 

Nightr 

H.C.O. 

P.  DM. 

H. 

P. 

H. 

P. 

se. 

0 

h      in       s 

o                  / 

B' 

+  35     146 

o     42     34 

+  35     39-5 

W  + 

8.02 

8.23 

7-93 

8.22 

-9 

-  i 

±2 

E' 

+  35     145 

o     42     33 

+  35     56-6 

W  + 

7.80 

8.03 

7-74 

8.03 

-6 

o 

±2 

/•' 

+  34     148 

o     50     45 

+  34     40-9 

w 

6.82 

7.26 

6.98 

7-27 

+  16 

+  i 

±2 

Mean.  .  . 

7-55 

7.84 

7-55 

7.84 

±10 

±i 

±2 

TABLE  16. — COMPARISON  STARS  IN  B.  D.  CATALOGUE. 


B.  D. 

1855- 

B.  D. 

1855- 

No. 

Mag. 

R.  A. 

Dec. 

No. 

Mag. 

R.  A. 

Dec. 

O 

h  m   s 

0      / 

O 

h  m  s 

0       / 

y 

+  34  120 

9-0 

o  41  36 

+  34  38-5 

1 

+  34  131 

9.2 

o  43  22 

+  34  55-7 

z 

+  34  121 

8-4 

0.42  6 

+  34  32-5 

E 

+  34  132 

9-i 

°  43  24 

+  34  45-7 

a 

+  34  "6 

9-1 

o  42  31 

+  34  45-9 

A 

+  35  i54 

8-9 

o  43  24 

+  35  3-6 

b 

+  34  "7 

8-3 

o  42  46 

+  34  39-0 

TABLE  17. — COMPARISON  STARS  FOR  V  ANDROMEDA  (IN  ORDER  OF  RIGHT  ASCENSION). 


Star. 

Coordinates  from  Variable. 

Light 
Scale, 
Steps. 

Magnitude. 

R.  A. 

Dec. 

Measured. 

From  Curve. 

H. 

P. 

H. 

P. 

y 

r 
u 
w 

q 
t 

* 

z 
s 

k 
g 

B 
k 
E 
D 
d 

} 
a 
m 
e 
b 

0 

n 
I 
A' 

H 

-442 
-408 
-388 
-374 
-315 
-286 
-272 
-172 

-    75 
-    68 

-    53 

—      12 

+    16 
+  "5 
+  119 
+  132 
+  139 
+  194 
+  224 

+  235 
+  258 

+  325 
+  423 
+  473 
+  549 
+  846 
+  883 

1 
-36.0 

-33-3 
-31.6 

-3°  5 

-25-7 
-23-3 

—  22.2 
-I4.I 
-     6.1 

-    5-5 
-   4-3 
—    i  .0 

+    1-3 
+   9-4 
+   9-7 
+  10.8 

+  11-  3 
+  15.8 
+  18.3 
+  19.2 

+  21  .O 
+  26.5 

+  34-5 
+  38-5 
+  44-7 
+  68.9 
+  72.0 

H 

-777 
-275 
+  342 
+  206 

-255 
+  291 

-323 
-165 
—  "56 
+  396 
-187 
-156 
+   9° 
+  152 
+  547 
-    26 
+    96 
+    74 
-748 
-354 
-107 
-185 
-765 
+    5i 
-    15 
+  296 
+  714 

4i-5 

9-27 

9-56 

I2± 

ii  .  29 
ii  .42 

I2± 
II  .42 

ii.  5± 
12-5 

11.58 
11.71 

26.1 
25-1 

...    . 



25-1 

11.71 

16.  o 

23.1 

17-7 
20.4 

4-7 
"-5 

"s.'a's 

13.82 
13-04 

'^52 

14.  ii 

'3-33 

12.8 

11.97 
12.63 

12.  29 

11.68 
12-34 

12.00 

9± 

9i 
o 
23.0 

3i   i 
37-4 
20.9 
26.5 
44.6 
23-9 

13-46 
14.  26 
11.83 
10.41 
9.91 
12.24 
ii  .  26 
8.81 

13-75 
'4-55 

12.  12 
IO.70 
IO.  2O 

12-53 
ii   55 
9.  10 



11.87 
II  .46 
9.6l 

9   •*? 

11.58 
ii.  17 
9  32 
8.98 

41.4 
43-9 



STELLAR    PHOTOMETRY. 
+  305 


N 


PLATE  3. 
-39s 


'K 


d 

• 


• 
n 


•  s 


•B 

D  C 


O 


g*    -h 


•  u 


•t 


tr 


—  +  10' 


— +5' 


—  5' 


Scale,   i  mm=  7*.  5. 


267  V  ANDROMEDA. 

R.  A.  oh44m39s.7.     Dec.    4_35°  6'  30",   1900, 


'9»5 


CHAPTER   III. — V   ANDROMED/E. 

MAGNITUDE 


33 


30 


-.26 


/•» 13 


267  V  ANDFtOMEDAE. 


IO 


FIG.  7. — MAGNITUDE-CURVE  FOR  V  ANDROMEDA. 
TADLE  18. — 267  V  ANDROMED/E.     PHOTOMETER  MEASURES  OF  COMPARISON  STARS. 


1904  October  6.                                                 6-INCH.                                                               Fine. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings 

c. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

h   m 
22  53 

23  14 

o 
22 

19 

E' 
B' 

V 
z 
b 
a 

Tl 

F™, 
a 
b 

z 

y 

B' 
E' 

13.0  12.3  13.0 
13.8  14.0  13.7 
24.9  25.2  25.1 
16.9   18.1    17.5 

2O.  O    21.  O    21.3 
27.4    28.5    28.3 

35-3  35-o  35.7 

12.8     12.8    12.  7 
12.  O    12.2    12.7 
29.0    28.8    29.8 
21.7    21.3    22.  I 

20.  o  19.7  19.  i 

25.0    25.1    24.9 
13.7    14.0    14.0 
I3.I    13.1     13.2 

12.77 
13.83 
25.07 
i?  50 
20.77 
28.07 
35-33 
12.77 
12.30 

29.  20 
21  .70 
I9.6O 
25.00 
13.90 
I3-I3 

12.95 
13-87 
25-04 
18.55 

21  .  24 
28.64 

0.63 
0.77 
2.13 
1.42 
1.74 
2.52 
3.38 
0.57 

7-77 
7.91 
9.27 
8.56 
8.88 
9.66 
10.52 
7-71 

8.06 

8.20 

9  56 
8.85 
9.17 

9  95 
10.81 
8.00 

12-54 

34  RESEARCHES   IN   STELLAR   PHOTOMETRY. 

TABLE  18. — 267  V  ANDROMEDA.     PHOTOMETER  MEASURES  OF  COMPARISON  STARS. — Continued. 


1904  October  30.                                               6-INCH.                                                               Good. 

Sidereal 
Time  . 

Zen. 
Dist 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

p. 

h    m 

21    29 

21    51 

0 

38 
34 

£' 
B' 

y 

s 

b 

a 
•v 
F' 
F'al 
F'm 
a 
b 

2 
If 

E' 

12.8  13.6  13.1 
15.1   15.2  15.7 
28.3  28.9  28.3 
18.4  18.2  19.  i 

22.0    23.1     23.2 
31.2    31.2    30.9 

49-7  49-3  49-4 
5.5     6.1      6.1 
14.9  14.1   14.1 

13-7   H-3  H-3 
32.8  32.9  32.7 
24.1   23.  i  24.2 
19.7   18.9  19.8 
28.0  28.2  28.3 

15-7  15-0  i5-i 
15.0  14.8  14.6 

I3-I7 
15-33 
28.50 

18.57 
22.77 
31.10 
49-47 
5  90 
H-37 
14.  10 
32.80 
23.80 

19-47 
28.17 

15-27 
14.80 

13-99 
15-30 
28.34 
19.02 
23.29 
31-95 

o-77 
0.98 

2-49 
i-47 
1.96 
2.92 
4.66 

O.O2 
0.83 

7-7i 
7.92 

9  43 
8.41 
8.90 
9.86 
n  .60 
6.96 
7-77 

8.00 

8.21 

9.72 
8.70 
9.19 
10.15 
11.89 

7-25 
8.06 

14.24 

1904  October  30.                                                                                                                Quiet,  dull. 

23  23 
23  4' 

20 

18 

b 
a 
z 

y 

B' 
E' 
E' 
B' 

y 

z 
a 
b 
F' 
F' 

25.8  26.7  26.7 
33-9  34-3  33-9 

19.2    21.2    20.2 
28.1    27.8    28.  I 
18.  I    17.9   17.8 
15.9  16.0  16.5 

I7.I    16.7    17.1 

18.3   18.1   18.7 
30.9  30.1  30.0 

21.  I    2O.  9    21.  0 

33-3  32-6  33.3 

25.2  25.0  25.5 

II  .  I    II  .0  II  .  I 
10.0  10.8  10.  i 

26.40 

34-°3 
20.  20 
28.00 

17-93 
16.  13 
16.97 
18.37 
30.33 

21  .OO 
33-07 

25-23 
II.O7 
10.30 

25.82 

33-55 
20.60 
29.17 
18.15 
16.55 

2.23 
3-13 

1.66 
2.58 
i-37 
1.16 

8.82 
9-72 

8.25 
9  '7 
7.96 

7-75 

9.11 

1O.OI 

8-54 
9.46 
8.25 
8.04 

10.69 

0.36 

6-95 

7-24 

1904  September  ii.                                            12-INCH.                                                           Good. 

21       8 
21    29 

42 

38 

y 

z 

b 
a 
e 
m 
d 
•v 
d 
m 
e 
a 
b 
) 
z 

y 

17.8  17.6  17.  I 
9-8     97     8.7 
27.8  27.0  28.  i 
13.1   13.2   14.0 
24.1  23.8  24.1 
34-9  35-2  35-8 
44-1  44-3  44-o 

40.9    40.7    41  .2 
25.7    25.0    25.5 

37-9  39-2  38-3 
43-3  44-i  44-4 
36-1  37-3  36-8 
23.0  23.1  22.7 
14.7  14.3  14.7 
29.2  29.4  29.4 
8.6     9.7     9.0 
17.  i   16.8  17.4 

I7-50 
9.40 
27-63 

'3-43 
24.00 

35-30 
44-13 
40.93 
25-40 
38.47 
43-93 
36-73 
22.93 

'4-57 
29-33 
9.  10 
17.  10 

17-30 
9-25 
28.48 
14.00 

23-47 
36.02 
44-03 
39-70 

1.38 
0.36 
2.50 
0.92 
2.06 
3-32 
4.22 

3-75 
2.24 

9.28 
8.26 
10.40 
8.82 
9.96 

11.22 
12.  12 
11.65 

16.  14 

9-57 
8-55 
10.69 
9.11 
10.25 
11.51 
12.41 
11.94 
10-43 

CHAPTER   III.  ^V     ANDROMEDA.  35 

TABLE  18. — 267  V  ANDROMEDA     PHOTOMETER  MEASURES  OP  COMPARISON  STARS. — Continued. 


1904  October  30.                                          12-INCH.                                                                  Good. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

/(     nt 

22    30 
22    50 

O 

27 
23 

y 

z 
b 

f 
a 
e 
m 
d 

V 

d 
m 
e 
a 

b 

2 

y 

15  8  16.3  16.0 
7.8     8.1     8.7 
12.4  13.1    13.1 
24.8  25.8  24.0 
20.  o  20.  o  20.  o 
35-o  35.1   34.8 
41.  7  42.0  42.0 
37-8  39.1   39-2 
33-o  33.9  33.8 
38-7  38.5  39-2 
42-3  40-9  4'-9 
32-2  33.0  32.8 
22.7  22.3  22.4 
27.2  26.3  27.3 

12.  O    12.8    12.4 

5-9     6.9     7.7 
14.0  14.6  14.8 

15-03 

8.20 

12.87 
24.87 
20.00 

34-97 
41.90 
38-70 
33-57 
38.80 
41.70 
32.67 
22.47 
26.93 
12.40 
6.83 
'4-47 

«4-75 
7-52 
12.64 
25.90 

21  .24 
33-82 
41.80 
38.75 

I  .02 
O.  21 

0.75 
2.27 
1.85 
3.06 
3.98 
3.63 
3-03 

9.14 

8.33 
8.87 
10.39 

9  97 
11.18 

12.  IO 

n-75 
11.15 

9-43 
8.62 
9.  16 
10.68 
10.26 
11.47 

12-39 

12.04 
11.44 

1904  November  i.                                                                                                                       Good. 

21    15 
21  33 

40 
37 

y 

z 
b 

f 
a 
e 
d 
m 

V 

m 
d 
e 
a 

I 

2 

y 

23.1   23.9  23.7 
16.2  15.9  15.0 
21.8  21.3  20.7 
35-i  35.9  34.3 
30  .  2  29  .  8  29  .  8 
43.6  44.2  43.9 
52-3  52-9  52-3 
55-5  56.7  57-4 
46.1  45.9  45-0 
55-0  55-5  55-7 
50.1  50.1  49.8 
43-0  43-9  43-i 
30-7  3°-3  30-7 
36.7  36.0  36.0 
19.9  19.8  19.8 

15-0  15-5  '5-1 
25.0  24.4  24.7 

23-57 
15-70 
21.27 
35-io 
29-93 
43-90 
52.5° 
56-53 
45-67 
55-40 
50.00 

43-33 
30-57 
36.23 
19-83 
15.20 
24-70 

24.14 

15-45 
20.55 
35-67 
30.25 
43.62 
51.25 

55-97 

2.  12 
I  .  II 

i-77 
3-27 
2.68 

4-17 
4-93 
5-29 
4.40 

9.28 
8.27 
8-93 
'0-43 
9.84 

«i-33 
12.09 

12.45 
ii   56 

9-57 
8.56 
9.22 
10.72 
10.  13 
ii  .62 
12.38 
12.74 
11.85 

1904  November  2.                                                                                                                 Fair  to  good. 

21  57 

32    18 

33 
29 

y 

z 

b 
i 

a 
e 
m 
d 

V 

d 
m 
e 
a 

I 

2 

y 

22.  O    21.7    21  .7 
13.8    15.0    14.2 
19.8    18.3    19.2 

33-7  32-7  34-i 
27.0  28.  i   28.3 
42.9  41.7  41.8 
51.4  51.2  51.0 
46.5  46.3  46.6 
39.3  40.8  40.2 
46.5  46.9  46.0 
50.9  51.2  51.3 
40.0  41.2  40.0 
26.  i  27.0  26.8 
32.5  31.8  32.3 
17.7   18.1   18.6 
ii  .9  12.8  13.0 

21-7    22.2    22.3 

21.80 

14-33 
19.  10 

33  50 
27.80 

42.13 
51.20 
46.47 
40.  10 
46.47 

5i-i3 
40.40 
26.63 
32.20 
18.13 

12.57 
22.07 

21.94 

13-45 
18.62 

32-85 
27.22 
41.27 

Si.i? 
46.47 

1.91 
o  59 
1-55 
2-95 
2-39 
3-92 
4.92 
4.46 
3-80 

9-38 
8.06 
9.02 
10.42 
9.86 

"•39 
12.39 

n-93 
11.27 

9.67 
8.35 
93' 
10.71 
10.  15 
11.68 
12.68 

12.22 
11.56 

36  RESEARCHES  IN   STELLAR  PHOTOMETRY. 

TABLE  18. — 267  V  ANDROMEDA     PHOTOMETER  MEASURES  OF  COMPARISON  STARS.- — Continued. 


1902  February  12.                                           40-INCH.                                                   Fair  to  good. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

h  m 
4  42 

0 

e 
m 
d 
D 
B 
C 

V 

E 
d 
tn 

ea2 
dat 

17.5  18.0  19.0 
24.8  25.2  25.0 
19.2  20.  o  19.3 
38.8  39.7  40.1 
31.8  32.8  32.0 
37-i   38.2  37.0 
30.8  32.3  32.0 
35-0  35-3  34-8 
19.5  21.8  20.  o 

23.2  24.4  23.7 

16.0  15.9  16.  i 
27.2  28.  i   27.2 
32-8  31.7  33.8 

18.17 
25.00 
19  50 
39  53 
32.20 

37-43 
3i-7o 
35  03 
20.43 

23-77 
16.00 

27-50 
3»-77 

17.09 
24-39 
19-97 

1-35 
2.'5 
i  .69 

3-72 
2.88 
3-48 
2.83 

3-20 

ii  .42 

12.22 
11.76 
13    79 
12.95 
'3-55 
12.90 
I3-27 

11.71 
12.51 
12.05 
14.08 
13-24 
13-84 
13-19 
'3-56 

2.42 
2.95 

1902  December  26.                                                                                                           Clear,  unsteady. 

2  45 
3  25 

e 
m 
d 
D 
B 
C 

V 

E 
E 
C 
B 
D 
d 
m 
e 
Caz 

21.4    22.8    22.5 
36.4    35.8    35.8 

29-9  30-9  31.0 
58.7  57-2  58.2 
42.2  43.6  44.6 

52.5  53-3  53-7 
47-2  45.2  48.2 
49.9  49.8  49.7 
49-9  50  8  49.8 
54-2  53-8  55-8 
45.8  45.2  45.8 
54-7  55-7  57-2 
3i-3  32-8  31.7 
35-4  36-2  37.0 
25.0  26.0  25.0 
39.8  40.7  40.2 

22.23 
36.00 
30.60 
58.03 
43-47 
53-17 
46.87 
49.80 

50.17 
54.60 
45.60 
55-83 
31-93 
36.20 

25-33 
40.23 

23-78 
36.10 
31.27 
56.93 
44-54 
53-89 

2.  IO 
3-32 

2.78 

5-34 
4.28 

5-15 
4-50 
4.80 

11.17 

12,39 

11.85 
14.41 
J3-35 

14.  22 

'3-57 
13-87 

ii  .46 
12.68 

12.  14 
14.70 
13.64 

H-5I 
13.86 

14.  16 

49  99 

3-80 

1905  January  28.                                                                                                                                Good. 

4  55 
5   '7 

49 

53 

e 
m 
d 
B 
D 
E 

1! 

C 
C 

•v 
E 
D 
B 
d 
m 
e 

18.3  19.8  20.  o 
24.0  24.5  24.4 

21  .9    22.2    22.8 

34-6  33.2  34.2 

44.1    45.1    45.8 
37.8    38.8    37.3 

35  o  37.0  36.0 
40  .  2  40  .  8  40  .  7 
40.1  40.3  39.9 
37-7  36.0  36.0 
34-'   34-i  35-2 
43-9  44-5  45-2 
34-2  32.0  31.8 
19.0  18.7   19.  i 
22.5  21.8  21.3 

17.2  17.8  17.5 

19-37 
24.30 
22.30 
34-oo 
45-00 

37-97 
36.00 

40.57 
40.  10 

36-57 
34-47 
44-53 
32-33 
18.93 
21.87 
17-50 

18.44 
23.08 
20.62 
33-  16 
44.76 
36.22 
36.18 
40.34 

1.50 
2.O4 
I.78 
3.00 
4-30 

3-33 
3-33 
3-8l 

n.  53 
12.07 
ii.  81 
t3  03 
14.33 
13-36 
13-36 
13-84 

11.82 
12.36 

12.  IO 
I3.32 
14.62 
13.65 
>3    65 

I4.I3 

CHAPTER    III. — V   ANDROMEDA.  37 

TABLE  18.— 267  V  ANDROMEDA.     PHOTOMETER  MEASURES  OP  COMPARISON  STARS. — Continued. 


1905  January  31.                                                   40-INCH.                                                                Good. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

h   m 

4  50 

5  04 

• 

50 

52 

e 
m 
d 
B 
D 
E 

V 

C 
C 
•v 
E 
D 
B 
d 
m 
e 

26.  i   27.2  26.4 
33-0  33  '   33-0 

27.  2    28.0    27.7 
39.8    40.  I    40.4 
52.2    53.7    52.8 
44.0    44.3    44.0 
40.8    41.8    41.7 
44.8    46.9    45.9 
45.6    44.8    45.0 
41.7    41.6    41.5 
42.4    41.4    41.9 
52.2    52.6    51.5 
36.0    37.9    36.2 
23-7    24.3    23.7 
28.8    27.7    3O.O 

21  .6  21.8  22.7 

26.57 
33-03 
27  63 
40.  10 
52.90 
44.10 

4i  43 
45.87 
45.13 
41  .60 
41.90 
51.  10 
36.70 
23.90 
28.83 
22.03 

24.30 

30.93 
25-76 
38.40 
52.00 
43.00 
41-52 
45-50 

2.14 

2-75 
2.27 

3-59 
4-99 
4.11 

3-95 
4-38 

"•55 
12.  16 
11.68 
13.00 
14-40 
13-52 
13-36 
13-79 

11.84 
12.45 
ii  97 
13.29 
14.69 
13.81 
13-65 
14.08 

TABLE  19. — 267  V  ANDROMEDA.    CONSTANTS  FOR  REDUCTION  AND  COMPARISON  WITH  CATALOGUE 

MAGNITUDES. 


6-INCH. 

Star. 

1904 

October  6. 

1904  October  30. 

1904  October  30. 

C. 

Obs. 

Mag. 

A  Mag. 

C. 

Obs. 

Mag. 

4  Mag. 

C. 

Obs.  Mag. 

A  Mag. 

H. 

P. 

H. 

P. 

H. 

P. 

H. 

P. 

H. 

P. 

H.        P. 

B' 

0.77 
0.63 
0.18 

7-91 
7-77 
6.96 

8.20 

8.06 
7-25 

—  .  ii 
-•03 

+  .14 

-  03 
+  .03 
—  .01 

0.98 
0.77 
0.08 

7.92 

7-7« 
7.02 

8.21 

8.00 
7-31 

-.10 

-.09 

f  .20 

—  .02 
-•03 
+  .06 

1-37 
1.16 
0.36 

7.96 
7-75 
6-95 

8.25 
8.04 
7-24 

—  .06  -1-  .02 
-  .05  +.01 

+  .13  -  .02 

E'  

F'  

Means  .  . 
M.  

0.41 

7-55 

7-14 

7.84 
7-43 

±.09 

i    O2 

0.61 

7-55 
6-94 

7.84 
7-23 

±.13 

±.04 

0.96 

7-55 
6-59 

7.84 
6.88 

±.08  ±.02 

12-INCH. 

40-INCH. 

.  Star. 

Mag. 
6-inch. 

C. 

Star. 

Mag. 
1  2-inch. 

C. 

Sept  1  1. 

Octso 

Nov.  i. 

Nov.  2. 

Feb.  12. 

Dec.  26- 

Jan.  28. 

Jan.  31. 

9-75 
8.87 
9.29 
8.41 

2 
0 
I 
O 

.06 

•92 
•38 
•36 

1.85 
o.75 
i  .02 

O.2I 

2.68 
i-77 

2.12 
I  .  II 

2.39 
1.55 
1.91 

0.59 

d 

ii. 

ii  . 

12. 

85 
28 
26 

1.69 
1-35 
2.15 

2.78 

2.10 

3-32 

1.78 
1-50 
2.04 

2.27 
2.14 
2.75 

g 

e  .  . 

m 

Me 
Me 
M. 

z  

anC  . 

Mean  C 

I 
9 
7 

.18 
.08 
.90 

0.96 
9.08 
8.12 

1.92 
9.08 
7.16 

1.61 
9.08 
7-47 

i-73 
11.80 
10.07 

2-73 
11.80 
9.07 

1.77 
ii  .80 
10.03 

2.39 
1  1.  80 
9.41 

Mean  Mag 

M0  . 

9.08 

an  Mag 

II. 

80 

RESEARCHES   IN   STELLAR   PHOTOMETRY. 
TABLE  20. — 267  V  ANDROMEDA.     MEAN  MAGNITUDES. 


6-INCH. 

Star. 

October  6. 

October  30. 

October  30. 

Mag. 

A  Mag. 

Mean. 

Mag. 

A  Mag. 

Mag. 

A  Mag. 

Mag. 

A  Mag. 

Mag.H. 

Mag.  P. 

A  Mag. 

B'.. 
E'... 
F'... 

a.  ... 
6.... 
y  
z  

7-91 

7-77 
6.96 

Mean. 

—  O.O2 

+  0.03 

—  O.O2 

7.92 

7-7i 
7.02 

—  O.OI 

—  0.03 
+  0.04 

7.96 

7-75 
6-95 

4-0.03 
4-0.01 
—  0.03 

7-93 

7-74 
6.98 

8.22 

8.03 
7-27 

±0.02 

±0.02 
±0.02 

7-55 

7.84 

±O.O2 

9.66 

8.88 

9-27 
8.56 

Mean. 

—  0.09 

+  O.OI 
—  O.O2 

+  o.  15 

9.86 
8.90 

9-43 
8.41 

+  O.  II 

4-0.03 
4-0.14 
o.oo 

9.72 
8.82 
9.17 
8.25 

—  0.03 
—  0.05 

—  O.  12 

—  o.  16 



9-75 
8.87 
9.29 
8.41 

10.04 
9.  16 

9-58 
8.70 

±0.08 
±0.03 
±0.09 
±O.  IO 

9.08 

9  38 

±0.08 

i 

12-INCH. 

Star. 

September  1  1  . 

October  30. 

November  i. 

November  2. 

Mean. 

Mag. 

A  Mag. 

Mag. 

A  Mag. 

Mag. 

A  Mag. 

Mag. 

A  Mag. 

Mag.  H. 

Mag.  P. 

A  Mag. 

a.  ... 
6.... 
y  

2.  ... 

e.  .  .  . 
d.... 
m  .  .  . 
}.... 

9.96 
8.82 
9.28 
8.26 

Mean. 

II  .22 

11.65 

12.  12 
10.40 

Mean. 

+  0.05 
—  0.09 

4-O.OI 

+  0.03 

9  97 
8.87 
9.14 
8-33 

4-0.06 
—  0.04 
-0.13 

+  O.  IO 

9.84 

8-93 
9.28 
8.27 

—  0.07 

4-O.O2 

4-0.01 
4-0.04 

9.86 
9.02 
9-38 
8.06 

—0.05 
4-0.  ii 
4-o.n 
-0.17 

9.91 
8.91 
9.27 
8.23 

IO.2O 
9.  2O 

9  56 

8.52 

±0.06 
±0.06 
±0.06 
±0.08 

9.08 

9-37 

±0.06 

—  0.06 

—  O.2O 

—  o.  14 

—  O.OI 

II.  18 
11-75 

12.  IO 
10.39 

—  O.  IO 
—  O.  IO 

—  o.  16 

—  O.O2 

"•33 
12.09 

12.45 
10.43 

4-0.05 
4-0.24 
4-0.19 

4-0.02 

"•39 
n-93 
12-39 
10.42 

4-o.  ii 
4-0.08 
4-0.13 
4-0.01 

11.28 
11.85 
12.26 
10.41 

11-57 

12.  14 

12-55 
10.70 

±0.08 
±0.15 
±0.14 
±0.01 

ii  .46 

ii-75 

±O.  IO 

40-INCH. 

Star. 

February  12. 

December  26. 

January  28. 

January  31. 

Mean. 

Mag. 

A  Mag. 

Mag. 

A  Mag. 

Mag. 

A  Mag. 

Mag. 

A  Mag. 

Mag.  H. 

Mag.  P. 

JMag. 

d  

e  
m  .  .  . 

B.... 
C.... 
D... 
E.... 

11.76 
11.42 

12.22 

Mean. 

12.95 
13-55 
13-79 
13.27 

Mean 

o.oo 
—  0.04 
+0.04 

11-85 
It.  17 

12.39 

4-0.04 
—  o.  16 

4-O.I2 

11.81 

Ji-53 
12.07 

4-0.05 
4-0.07 

—  O.  II 

11.68 
"•55 

12.  id 

-0.08 
4-0.09 

—  O.O2 

11.76 
ii  .46 
12.  18 

12.05 
iJ-75 
12-47 

±0.06 

±O.  II 

±0.08 

11.80 

12.09 

±0.08 

—  O.II 

—0.29 
-0.49 

—  O.2I 

13-35 

14    22 
14.41 
I3-87 

4-0.09 
4-0.05 
—  0.18 
4-0.09 

13-03 
13-84 
14-33 
13  36 

—0.03 
o.oo 
4-0.05 

—  O.I2 

13.00 

13-79 
14.40 
I3-52 

—  O.O6 
—  0.05 

4-o.  12 

4-O.O4 

13.06 

13-84 
14.28 

I3-48 

13-35 
H-I3 
H-57 
13-77 

±0.06 
±0.03 

±O.  12 
±0.06 

11.66 

13-95 

±0.07 

CHAPTER   III. — V   ANDROMEDA. 


TABLE  21. — 267  V  ANDROMEDA.     VISUAL  OBSERVATIONS  OP  THE  VARIABLE. 


No. 
i 

2 
3 
4 
5 
6 

8 
9 

10 

ii 

12 

13 
H 

15 
16 

17 
18 

19 

20 

21 
22 

23 
24 
25 
26 

27 

28 

29 
30 

3' 

32 
33 

34 

35 
36 

37 
38 

39 
40 

42 

Date. 

Ocular. 

Aperture. 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing. 

t. 

A  Mag. 

Month 
and  Day. 

Hour 
C.  S.T. 

Julian 
"Day. 
G.  M.  T. 

Steps. 

Mag. 

1897 
Jan.    19 

21 
22 

28 
30 

May  24 
July   21 

27 
Aug.     3 

8 
ii 
19 

27 
Sept.    5 

13 
16 

20 

21 

25 
29 
30 

Oct.    14 

25 
Nov.  16 
Dec.   29 

1898 
Jan.    1  6 
18 
Feb.    15 

23 
Mar.     4 

'3 
16 

23 
28 
Apr.    15 
June  27 
July     6 

12 

25 

Aug.   9 
17 

8 
8 
7 
7 
7 
15 

10 
10 

9 
16 

9 
9 

9 

7 
8 

7 
9 

8 

«7 

8 

7 
16 

7 
7 
7 
7 

7 
7 
8 

7 
7 

7 
7 

7 

7 
16 

'3 
ii 

ii 

12 
IO 
II 

2410000+ 
3944-58 
3946.58 
3947  •  54 
3953-54 
3955-54 
4069  .  88 
4127.67 
4I33-67 
4140.63 

4I45-92  { 

4148.63 
4156.63 

4164.63  -j 

4I73.54 
4181.58 
4184.54 

4186.63 

4188.58 

4189.96 
4193.58 
4I97.56 
4198.94 

4212.54 
4223.54 

4245.54 
4288.54 

4306.54 
4308  .  54 
4336.58 
4344-54 
4353-54  | 
4362  .  54 

4372.54 

4377-54 
4395-92 
4468.89 

4477-71 
4483-7I 

4496.  85  j 

45"-77 
45I9-7I 

80 
40 
150 

150 
150 
150 

40 
40 
40 
150 
80 
150 
150 
40 
150 
150 
150 

150 

150 

150 
150 
150 
150 
150 
150 
150 

150 
150 
150 
150 
40 
150 
150 
40 

40 

40 
40 
80 
80 

275 
80 

275 
460 

'75 
275 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

6 

6 

6 
6 
6 
6 
6 
6 
6 
6 

6 
6 
6 
6 
6 
6 
6 
6 

6 

6 
6 

12 
12 

12 

12 
12 
40 
12 

12 

/2D,  1)1-26  

29.  i,  28.0  

28.5 

ii  .00 

moon 
poor 
good 

fair 
fair 
good 
good 
fair 

poor 

good 
good 

moon 
moon 
fair 

o 

2 

3 
9 
ii 
126 

184 
190 
197 

202 

205 
213 

221 

230 

238 
240 

-0.33 
-0.23 

+  O.  12 
+  0.16 

+  0^6 
+  0.49 

+  0.52 

+  0.50 
+  0.51 

+  0.40 

+  0.65 
+  0.32 
+  0.52 

v  not  seen  

1)30"  DO—  16  /4D  

26  o  27  o,  27  .  i  ... 

26.7 

22.  I 
21  .  I 
<23 

34-7 
38.6 

36.9 
35  9 

35-7 
34-2 

33-4 
29.1 
29.  i 
27.1 

11.25 
11.79 
ii  .91 
<n.7 

IO.2I 
9.69 
9.91 

IO.O4 

IO.O8 
10.28 

10.37 
IO.9T 
IO.9I 
II.I8 

62-3D,  D2d,   vg,  vi-2h.  .  .  . 
vd,  vi-2h  
d  glimpsed,  D  not  seen  .... 

24.0,  25.0,  20.4,  19.2. 
23.0,  19.2  

71:  I.  -14.  4.  . 

via  /2—  3D 

38  4  38  9 

l^-yj,  DO,  D6/  

*4D 

36.4,  37-4,  37-i  •  • 
-374..  .  .  ) 

"*  ,  

O2D,  D4/  
O2V  D5/  

35-4,  35-1  > 

-1C  J.  l6  I 

030  D3/  

32.4.  34-1  ) 

-1-1  A  "7  7  6  .  .  i 

dIOV,  DI-2/  
/2V  D  limit  

27-4,  29.6  

/4~  5D,  1)26,  vdg  
(&6o  aio/  /2e  fh  7130 

26.6,  28.5,  26.4  .  . 

f 

f/5»,  DI—  26,  1>4d,  Vlt,  VU.  .  ~| 

j  i>3«,  7146,  63d,  d4O,  03771..  1 
j  tyu,  d$g,  g2h,  p^q,  pi-2r  .  j 
Lp2-u  limit  4<wi  J 

26.  i,  28.0,  27.0,  ) 
26.1 
26  .  i    26  .  i  ) 

26.5 

25-7 
22.9 

23-' 
20.7 
17.1 
16.1 

«^  I  o 

^  IO 

^  IQ 

25-5 
31-2 

31.2 

35-8 
37-7 
43-8 

45-0 

46  ± 
20.  6 

21  .O 

I6.3 

"•3 

4-7 

11.26 

"-35 
ii  .70 
11.67 
11.97 
12.40 
12.51 

<I2.3 
<I2.2 

<I2.2 
<I2.2 

"•37 
10.67 

10.67 

10.08 
9.81 

9.00 

8.81 
8.7± 
11.98 

"•93 

12.49 

<I2.5 

I3.83 

good 
good 
good 
good 
good 
good 
fine 
moon 

good 
good 
good 
good 

fair 

good 
good 

fair 

good 
poor 
good 
poor 

good 
good 

244 

246 
250 
254 
255 
IO 
21 

43 
86 

104 
106 

134 
142 

'Si 

10.) 

163 
170 

175 
194 

9 

ii 

24 

37 
52 
59 

+  0.45 

+  0.43 
+  0.67 
+  0.50 
+  0.76 
+  0.69 

+  0.4J 

+  0.03 
—  0.24 

+  o  16 

—  0.09 
-0.25 

—  0.80 

-0.79 
-o.7± 
+0.30 
—  0.06 

+  0.31 
+  0.46 

+  0.53 

23.5,  26.0  
22.5,  24.0,  21.4  .  . 
23.0,  24.0,  22.4 

22.  0,  2O.4,  19.7  .  . 
16.4,  17.9  
15-4.  16.9  

6  ID,  D3d  
641),  Did,  DIJ/  

63-40,  v*di  V2S  
diD,  vg,  V2h  
</4D,  TO  3D,  i'  limit  
<75D,  77141),  limit  D  
v  not  seen  limit  5  <d  

v  not  seen,  limit  i—2<g.  .  .. 

v  not  seen  limit  g  and  h  .  .  . 

v  not  seen,  limit  i  <J?  

D2OT,  712D,  /2-3D  
05—61)  D271  

22.9,  25.2,  28.6 

33-6,  29.2,  30.9  .  . 

31  .  Q.  29  .  2  .  .  .  ) 

O5D,  D471  

02D,  Dioe,  D?/,  i)6n,  nif  .... 
i)Z  i  ,  difficult  

32.4,  31-2  i 

35-4,  36.5,  38.1,  33-2 
36.4,  38.5,  38.4  .  . 
\4l.9,  44-6,  43-81 

44-3.  45-5,  44-4,  45-9 

div,  vim,  v^A  
d2i>  TJ  glimpsed  

22.  0,  19.9,  2O.  O  .  . 

dyv,  041),  h2v,  v^B,  vA  .... 

43-41;,  -viB  
BID,  D4C,  limit  C  

D  not  seen,  limit  6<d  or 

2<A 

d6B  BT,C,  Cv,  limit  D.  .  .  . 

f  18.0,   16.4,   15.7) 
\i5-5.   16.0  ) 

12.5,  12.5  ) 
io-5,  8.7  '- 
'4-5-  9-2  ) 
<i7,    <I5  

4o 


RESEARCHES   IN   STEUvAR   PHOTOMETRY. 


TABLE  21. — 267  V  ANDROMEDA.     VISUAL  OBSERVATIONS  OF  THE  VARIABLE. — Continued. 


No. 

Date. 

Ocular. 

t 
v 

P. 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing, 

t. 

A  Mag. 

Month 
and  Day. 

Hour 
C.  S.  T. 

Julian 
Day 
G.  M.  T. 

Steps. 

Mag. 

43 
44 
45 
46 

47 
48 

49 
50 

5' 
52 

53 
54 
55 
56 
57 
58 

59 
60 
61 

62 

63 
64 
65 
66 

67 
68 

69 
70 

71 
72 

73 
74 

75 

76 

77 
78 
79 
80 
81 
82 

83 
84 

85 
86 

87 
88 
89 

90 

1898 
Oct.    1  1 
Nov.     2 

12 

19 

Dec.     3 
9 

17 
28 

1899 
Jan.      2 
9 
19 
28 
Feb.      7 
28 
Mar.   13 
July   29 
Aug.  10 
26 
Sept.  n 

20 
Oct.        2 

7 
23 
30 
Nov.     4 
20 
26 
Dec.     5 

19 

28 

1900 
Jan.      2 
24 
26 

Feb.     4 

22 

24 

Mar.     7 

21 

May   20 
June  25 
July  30 
Aug.  26 
Sept.    6 

Oct.      4 
18 
23 

1901 
Feb.     9 

7 
7 
8 

7 
7 
6 

7 
6 

6 
6 

7 
6 

8 
8 
IO 

9 
9 

8 

8 
8 
7 
7 
7 
7 
7 
6 
6 

6 

6 
7 
6 

8 

8 
9 

's 

J4 

IO 

8 
ii 

7 

IO 

6 

9 

2410000+ 

4574-54 
4596.54 
4606  .  58 

4627.54 
4633-50 
4641  .  54 
4652.50 

4657-50 
4664  .  50 

4674-54 
4683  .  50 

4693-54 
4714.62 

4865.67 
4877-63 
4893-63 
4909.58 

4918.58  -J 

4930.58 
4935-54 
4951-54 
4958  .  60 
4963-50 
4979-54 
4985  •  So 
4994-52 
5008.54 
50I7-50 

5022  .  50 
5044-54 
5046  .  50 

5055-58 

5073-58 
5075-63 
5086  .  6  ' 
5100.58 
5160.83 
5196.83 
5231-67 
5258.58 
5269.71 

5278-54 
5297.88 
53II-67 
5316.50 

5425.63 

80 
150 
ISO 
150 
40 
40 
40 
40 

40 
40 
40 
40 
40 
150 
150 
150 
40 
40 
40 
150 
40 
40 
40 
150 
150 
ISO 
150 
150 
150 
200 
150 

200 
150 

350 

350 

350 
'75 
275 

40 
40 
40 
150 
237 
150 
350 
237 
237 

40 

6 
6 
6 
6 
6 
6 
6 
6 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

6 
6 

40 

40 
40 

12 
12 
12 
6 
6 

6 
6 
40 
6 
40 
40 
40 

6 

v  not  seen,  limit  4<d.,  .  . 

23.1 
27.4 
30.2 

36.4 

41  .0 

43-1 
41.1 

41  .6 
4i-3 
39-7 
37-4 
32-7 
28.3 
24.0 

30.7 

34-2 
38-5 
40.  i 

37-5 

38.6 
38.6 
37-9 
33-2 
33-3 

29.  2 

25-4 
24.2 
2O.9 
18.4 

18.2 
7-9 

7-9 

n.  i 
11.4 

21.4 
31.2 
42.6 
39-2 

28.7 

21.2 

18.2 
"   9± 

5.9 

7.4 

41.7 

<I2.2 

II  .67 

11.13 
10.73 

9.98 

9-37 
9.09 

9-34 

9-30 
9-32 
9-54 
9.86 
10.47 

II.  OI 

"-57 
10.72 
10.27 
9.70 
9-49 
9-83 

9-70 
9.70 
9.80 
10.40 
10.39 
10.90 
11.38 

n-53 
n  .96 
12.25 

12.28 

<I2.2 

'3-49 

13-49 

10.13 

13.05 
11.88 
10.67 

9-»5 
9.60 
10.97 
ii  .90 
12.28 

<I2.2 

I3-70 
13-53 

9.27 

fair 
good 
good 
good 
good 
good 
good 
good 

good 
good 
good 
good 
good 
good 
low 
good 
good 
good 

good 

good 
good 
good 
good 
good 
fair 
good 
good 
good 
good 

good 
good 

fair 

good 
good 
fair 
good 
fair 
good 
good 
fair 
good 
good 
poor 
good 
good 

fair 

114 

136 

146 

153 
167 
173 

181 
192 

197 
204 
214 
223 
233 
254 
9 
148 
1  60 

175 
192 

200 

212 
217 

233 
240 

245 

3 
9 

18 

32 
41 

46 
68 

70 

80 
98 

IOO 

no 
124 
185 

221 

256 

24 
36 

44 
64 

78 
82 

192 

+  0.48 
+  0.36 
+  0.33 
+  0.08 
-0.31 
—  0.30 

—  O.O2 

—  0.  12 

—  o.  24 

-0.23 
+  O.O9 
+  O.  IO 

—  o.  18 

—  0.  II 

+  0.04 
+  0.09 

+  O.  IO 

+0.13 
+  0.35 

—  0.04 

-0.17 
-0.58 

—  0.27 
-0.30 

-0.58 

—  o.  29 

-0.45 
-0.48 
-0.49 

—  0.62 

+  O.O2 
O.OO 

o.oo 

+  O.O2 
-0.63 
-I.I4 
-0.17 

-°-37 
—  o  30 
-0.27 
—  0.30 

-o.i± 

+  O.2I 
+  0.05 

-0.08 

vi—  2<j  vid  eyv 

21.9,  24.0,  23.5  .  . 
27.0,  28.5,  26.7  .  . 
27-4,  29.2,  34.1   .. 

v^.dt  V2et  no~iv  

dlOVt  V271,  V$f  
Q.IV  VlEf 

via  biv 

v^a,  biv,  viy  
vy,  A  '31?,  v^a,  641?  

viy,  A'$i>,  v^a,  byv  .  .  .  . 
vy  A  *2V  v^a  641?  .  . 

42-4,  43-6,  43.6  .  . 
41.5,  40.9,  42.4,  39.6 

42.5,  40.9,  41.4,  41.6 
41.5,  41.9,  41.4,  40.6 
39-9,  40.1,  39-5,  39-4 
37-9,  37-5,  36-4,  38.1 
32.4,  30.7,  35-i   .. 
30.4,  27.2  27.5  .  .. 

A'qv,  64—  5V,  y2V,  V2d.  .  . 
A'6v,  y^v,  aiv,  v6-8/.... 

ajv,  vn,  1)4-50"  
Did  

/ID,  D3~  471,  D5«  

D6/,  DIO,  64-50  
h-2D,  via  

DO  

30.1,  30.7,  31.5 

33-4,  35-i  
37.1,  38.4,  40.1 
40.9,  39.4  
•174.                          ) 

^3—  41),  DIO  

38  .  4,  37  9  .    .  .      ) 

DIO,  /4D,  64-5D  

Z2-3D,  D20,  &4-5D  
DO—  IO  

38.4,  37-4,  40-1 
38-9,  37-4,  40.1    .- 

O  <\V  Dd/  D  W 

32-4,  35-i,  32-2 
32-4,  35-i,  32-5   •  • 
27-2,  28.5,  32.0  .  . 
22.5,  27.2,  26.5   .  . 
22.5,  25.0,  25.2 

22.  0,    21  .9,    18.9    .  . 

05D,  vyn,  v(>e  
vn,  V2e,  vS-iod  
e4D,  vn,  ?  D3~4d  

eqV  D2d  712D  

dlD,  Vim,  OI-2D  

TO  2—  3D±  ,  limit  D  

my),  d4D,  limit  i)  
D  not  seen,  limit  2  <  m.  .  . 

17-4,    19-0  

(  fj  2V     1)40,    £j  4^  ,    ^  5-^-'  \ 
\  02O,    d^ffl,    fftoB,     />'/'.) 

(  £30,  1)3(7,  E2V,  v6C.  .  1 
^  d6m,  m8-ioB,  B^E  ..)- 
(£4-5.0,  limit  6-8  <Z>) 
V2E,  vB,  miov  
Bv,  V2E,  limit  E  

71     8.7  .. 

6.1,  7.7,  7.1,10.7.  . 

II.  i,   11.5,    10.9   .  . 
11.5     ii    i 

d2D,  Dim  
OIOD,  D/,  i'6—  8e,  viod.  .. 
A  'ID,  vy,  v6a  
64—  SD,  DIO  
v^d,  vim,  vf  
d2D,  vig  
0*51),  D6-8B  
D  glimpsed,  limit  3—  4<d  . 

21.  0,    21.9   
27.4,  31.1,  37.5,   33.0 

42.9,  4i-5,  43-4  •• 
40.1,  38.4  
27.0,  28.2,  31.1 

21.  0,    21.4  

18.0,  18.5  

E  and  D  glimpsed  

SID,  Di(7,  1)4.0  
B6v,  viE,  vzC  

vl,  D4-50  

8.1,  5.7,  4.0  
5-5,  10.  i,  6.7  

4i-4,  4i-9  

CHAPTER   III. — V   ANDROMEDA. 


TABLE  21. — 267  V  ANDROMEDA.     VISUAL  OBSERVATIONS  OP  THE  VARIABLE. — Continued. 


No. 

Date. 

IH 
,3 

Aperture. 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing. 

'• 

A  Mag. 

Month 
and  Day. 

Hour 
C.S.  T. 

Julian 
Day 
G.  M.   T. 

Steps. 

Mag. 

92 
93 
94 
95 

96 

97 
98 

99 

IOO 
IOI 
102 

103 
104 

105 
106 
107 
108 
109 
no 
in 

112 

113 
114 

»5 

1901 
Nov.     i 

1902 
Feb.    12 

23 
Oct.    31 
Dec.   26 

1903 
Oct.    ii 

1904 
Aug.  29 
Sept.  1  1 
Oct.     6 
Nov.  15 
29 
Dec.     5 

1905 
Jan.    28 
Feb.   25 
Mar.     5 
May   22 
Aug.     6 

9 

28 
Sept.  19 
Oct.      I 
20 
24 

Dec.   23 

7 

10 

7 
10 

10 

6 

7 

9 
7 
7 
15 
15 
'5 
9 
10 

9 

8 
8 

9 
10 

2410000+ 
5689.54 

5793-5 
5804 
6054.67 
6120.6 

6399-54 

6722 
6735-67 
6760.67 
6800 
6814.50 
6820.54 

6874.60 
6902  .  54 
6910.54 
6986.88 
7064.88 
7067  .  88 
7086.63 
7108.67 
7120.63 
7I39-58 
7143-58 
7150-63 
7203.69 

80 

237 

237 
237 

ISO 

67 
40 

40 

237 
237 
67 
2O 

237 
150 
ISO 

237 
237 
80 

237 
237 
237 

3 

40 

24 
40 
40 

6 
6 

12 

6 

24 
6 

12 

40 
40 
12 

5 
40 
6 
6 
40 
40 

12 
40 
40 
40 

A'm,  Tib  
•va-iB  

42-9,  44-6  

43-7 

12.  O 
6.9 

6-9 

8.1 

28.9 
33-6 

9.00 

13.00 
i3-6± 
13.60 
'3-45 

10.96 

JO.  35 
io.  14 
10.52 
12.3 

<I2.2 

12.  5± 

13-34 
11.79 
II  .60 
9.27 

".75 
II.80 
12.03 
13.35 
13  40 

<I3-0 
12.92 
12.78 
10.9 

fair 
good 

good 

fair 
good 
fine 

197 

43 

54 
47 

112 

133 

198 

212 

237 

—  0.42 

+  0.19 

+  0-43 
+  0.67 
+  1-03 

—  0.40 

+  0.93 
+  0.41 

—  O.O2 

photograph,  E$v,  v^C  .  .  . 
Em,  -viC  
Eyv,  Em,  v$C  

5-i,  8-7  
8.1,  5-7  

8  5  8  I  77 

"vjd,  1*46,  nm  

30.0,  30.5,  26.2. 

photometer  

photometer  

photographs  

v  not  seen,  limit  3—4  <  d  . 

^5.9 

fair 
good 

good 
good 
good 
fair 
good 
fair 
fair 
fair 
fair 
good 
good 
good 
fair 

32 

38 

92 
1  2O 
128 
204 

24 

37 
46 
68 
80 

103 
no 
163 

—  O.  12 

+  0.04 
—  O.2O 
—  O.O7 

-0-33 
-0.45 
-0.87 
—  0.90 
-0.13 
-0.05 
—  0.07 
+  0.07 
+  0.26 
+  0.9 

11  glimpsed,  m$'v±  

photometer  

dyv,  vyn  
AITJ   eiv    112m  . 

20.0,  23.9  
23-0,  25.5,  22.9. 
40.6,  43.4  
22.  0,  22.9  
20.5,  23.4  
18.5,  20.9  

7.5,  io.  i,  7.7  .. 
'0-5,  9-i,  5-7  -• 

22.  0 
23-8 
41.8 
22-4 
22.  0 
2O.  I 
8.9 

8-4 

12.7 
'3  9 
29 

dm,  vim  

^4-51;,  vm  
Bqv,  mE,  VT,C  
Bm,  T>E,  viC  
•v  not  seen,  limit  B  

•vi—  2B,  Tj^C,v5E,  m6-8v. 

13-0,  9.7,14.1,13.8 
14.0,  10.7,  12.8 

30.0,  26.4  

v6-8d,  010-121;  

RESEARCHES  IN  STELLAR  PHOTOMETRY. 


TABLE  22. — 267  V  ANDROMEDA.    MEAN  MAGNITUDES  PROM  21.5  DAY  GROUPS. 


Grou] 
r   D 

>  No  

i 

21  -5 

2 
4.1 

3 
64.  S 

4 
86 

5 
107.5 

6 

129 

7 
150.5 

8 
172 

9 
193.5 

IO 

215 

ii 
236.5 

12 

258 

r     t 

6 

187 

204 

226 

247 

M 

9-95 

IO.O8 

10.64 

II  .43 

3944    < 

AM 

+  0.62 

+  0.50 

+  O.  t-2 

+  0.52 

No 

2 

4 

2 

7 

r       / 

16 

138 

161 

175 

194 

M 

ii  .02 

9.89 

8.81 

8.7± 

4202   < 

JM 

4-O   "\5 

—  O.  IO 

—  o.  24 

—  0.79 

—  o.7± 

No 

2 

2 

4 

i 

i 

r        t 

14 

30 

59 

14! 

160 

182 

205 

228 

254 

M 

1  1    06 

12    78 

il  81 

1  1    4O 

10.38 

9.27 

9.39 

10.  16 

ii  .01 

4460   < 

JA/ 

-f-O    12 

+  o  18 

+  o  53 

+  O.42 

+  o.  20 

—  0.21 

—  O.20 

+  0.10 

-0.18 

No 

2 

2 

i 

2 

2 

3 

3 

2 

i 

< 

Q 

148 

1  60 

184 

206 

225 

242 

M 

II     C7 

10.72 

IO.27 

9.60 

9.76 

9-75 

10.50 

4718   < 

AM 

—  O    II 

+  O.O4 

+  O.O9 

+  O.  12 

+  0.16 

-0.38 

-0.28 

(_    No 

I 

j 

I 

2 

2 

2 

2 

4976   < 

r    J 

JM 
.    No. 

!< 

IO 
11.27 
-0.44 
3 

36 

12.  IO 
—  0.48 

2 

46 
12.28 
—0.62 

i 

64. 

75 
13-49 

+  O.OI 

3 
go 

99 
13.08 

+  0.01 
2 

"7 
11.28 
-0.88 

2 

185 
9-15 
-0.17 

I 

1  02 

221 
9.60 

-0-37 
I 

256 

10.97 
-0.30 
I 

M 

!•»     14- 

Q.27 

5234   " 

4M 

—  o  28 

—  O.O8 

No 

2 

I 

2 

I 

[/ 

197 

M 

9.OO 

AM 

—  0.42 

No 

I 

< 

48 

M 

it   14- 

575°   ' 

JA/ 

-j-o  31 

No. 

2 

/ 

H2 

M 

1  1   60 

I  3    d.^ 

AM 

+  o  67 

4.  I    03  ± 

No 

!t 

IH 

M 

JA/ 

No. 

[< 

2O5 

237 

M 

IO.24 

IO.52 

6524   ' 

AM 

+0.67 

—  O.O2 

No. 

2 

I 

!< 

18 

M 

12    S± 

AM 

—  O.  12 

+  o  04 

—  o  20 

No. 

Means 

f    « 

]     AM 
I    No. 

II 

u-75 

+  O.OI 
12 

32 
12.37 
-0.13 

7 

53 
13.26 
+0.16 
6 

82 
13.48 
+  0.06 

6 

99 
13.08 

+  O.OI 
2 

116 
12.17 

—  O.O2 

4 

140 
11.02 
—  O.OI 

6 

160 
10.18 

+  O.O2 

7 

184 

9-34 
—  0.08 
IO 

2O2 

9-53 
+  0.03 

13 

225 
10.04 
—  0.03 

7 

245 
10.89 
—  0.05 
12 

CHAPTER   HI  — V   ANDROMEDA. 


43 


SI 

• 
m 


e 
a\ 
to 


xio 

|        - 


Uj   0§ 

^.2g 


FIG.  8. — LIGHT-CURVE  OF  V  ANDROMKD*. 


44 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABLE  23. — 267  V  ANDROMEDJB.     OBSERVED  MAXIMA  AND  MINIMA. 
Elements  of  maximum.     1897  July  26  (J.  D.  2414132H2591  (E-i).     M-m=llld. 


MAXIMA. 

MINIMA. 

. 

Date. 

Mag. 

• 

Date. 

Mag. 

O 

Corr 

Wt 

^3 

Corr. 

Wt. 

K 

Calendar. 

J.  D. 

H. 

P. 

W 

Calendar. 

J.D. 

H. 

P. 

I 

1897  July  26 

4132 

97 

IO.O 

0 

10 

i 

1897  Apr.  10 

4025 

me 

+   4 

3 

2 

1898  Apr.  15 

4395 

8  70 

8.99 

+    4 

12 

2 

Dec.    8 

4267 

me 

-13 

4 

3 

Dec.  20 

4644 

9.  10 

9-39 

-   6 

2O 

3 

1898  Sept.   i 

4534 

13.90 

14.19 

-    5 

10 

4 

1899  Sept.  20 

4918 

9.40 

9.69 

+    9 

17 

4 

1899  May  to 

47«5 

me 

-13 

2 

5 

1900  May  17 

5157 

8.9 

9.2 

—  ii 

8 

5 

1900  Feb.    5 

5056 

13.4° 

13.69 

—    i 

21 

6 

1901  Feb.    6 

5422 

9-3 

9.6 

5 

I 

6 

Oct.  24 

S31? 

13-67 

I3-96 

+    i 

5 

7 

Oct.  22 

5680 

9.0 

9-3 

-    6 

I 

7 

1901  June  24 

5560 

me 

-"5 

i 

10 

1903  Dec.    i 

6450 

me 

-'3 

i 

8 

1902  Mar.    9 

,S8i8 

13.6 

13-9 

-16 

2 

ii 

1904  Sept.  9 

6733 

10.  10 

10.39 

+  n 

6 

9 

Dec.    4 

6088 

14.0 

14-3 

-   5 

3 

12 

1905  May    5 

6971 

9.06 

9-35 

—  10 

4 

12 

1905  Jan.  ii 

6857 

13-32 

13.61 

-J3 

4 

DAYS 
0                          /0<? 

Z(?^> 

300 

|     I     1 

• 

167 

/  AND 

Min. 
M-m- 

ffOM 

=    7* 
.  ///  « 

1   1  1 

f  5 

-1  X 

<y 

f 

\ 

r 

j       j 

3        -i 

IQ 

.i 

\ 

? 

I 

2" 

r 

_  r 

i 

\ 

r 

j 

-     -J      - 

T 

7 

r 

r  : 

w  "   . 

jA 

__[ 

Q          

^ 

V 

7 

•     r 

i 

J 

z 

o 

n 

r 

I 

2        

s 

f 

. 

, 

1 

] 

T 

':: 

\ 

1 

i 

7 

\ 

r 

M 

* 

'J 



t. 

\ 

4  v 

x  ,  ; 

^ 

±7 

7 

> 

/4   .- 

FIG.  9. — MEAN  LIGHT-CURVE  OF  V  ANDROMEDA. 

See  Table  22,  page  .42. 


CHAPTER  IV. 


787  W  ANDROMEDA. 
R.  A.  2h  11°>  14M;  Dec.  +43°  50'  26"  (1900). 

This  is  another  of  Anderson's  discoveries,  announced  in  the  Nachrichten  under 
date  January  8,  1898.  Observations  began  at  once  with  the  star  on  the  descending 
branch  of  the  light-curve.  The  first  minimum  was  below  the  limit  of  the  6-inch, 
but  the  following  maximum  was  well  covered  and  the  second  minimum  was  ob- 
served with  the  12-  and  4O-inch  telescopes,  then  followed  occasional  observa- 
tions, frequent  enough  to  fix  the  number  of  the  epoch,  till  the  minimum  and 
maximum  of  1904  and  1905,  for  which  more  numerous  observations  were  made. 
Comparing  with  the  earlier  dates  the  period  396  days  was  found  and  the  mean 
light-curve  deduced,  using  comparisons  up  to  February  25,  1905.  The  subsequent 
maximum,  1905  May  31,  indicates  a  slightly  longer  period,  perhaps  397  days. 

The  characteristic  features  of  the  light-curve  are :  first,  a  large  range,  from 
about  7th  to  fainter  than  i3th  magnitude;  second,  a  steady  variation,  unbroken 
by  secondary  curves,  therefore  the  normal  points  from  Table  31  lie  close  to  the 
mean  light-curve. 

The  comparison  star  c  has  been  suspected  of  variability  by  Hagen  (A.  N.  164, 
79), and  confirmatory  observations  are  given  by  Williams  (A.  N.  164.  370-  Pro- 
visional magnitudes  were  published  by  the  writer  in  A.  J.  24,  25.  To  give  an 
idea  of  the  possible  variation,  these  are  summarized  below,  Williams'  observations 
being  reduced  to  magnitudes  by  assuming  his  star  a  (my  6)  to  be  9.53,  and  his 
star  b  (my  /)  to  be  9.57. 


Hagen. 

Williams. 

Parkhurst. 

Date. 

Mag. 

Date. 

Mag. 

Date. 

Mag. 

1900    Nov.  12 

99 

1900  Dec.    13 

9-55 

1899  Feb.     6 

9-5 

1901    Feb.     6 

9.2 

21 

9.70 

Oct.    1  8 

9-5 

10 

9.2 

1901  Jan.    14 

9.60 

23 

9-4 

Oct.    15 

9.2 

Feb.   13 

9.38 

28 

9-3 

Nov.  21 

9.2 

15 

9.42 

Nov.    4 

9.2 

1902    Oct.     8 

8.9 

1902  Jan.    31 

9.68 

1900  Feb.   1  6 

9.6 

1903    Sept.  22 

8.8 

Dec.   29 

9,62 

1902  Feb.     4 

9-27 

24 

8.8 

3' 

9.70 

Mar.     4 

9.14 

Oct.     20 

8.8 

27 

9.20 

Nov.  1  8 

8.9 

Oct.   29 

9  '3 

1903  Nov.  17 

9.24 

18 

9-3« 

19 

9.26 

Dec.     6 

9-23 

21 

9.40 

Nov.  ii 

9-15 

1904  Oct.    30 

9.19 

45 


46 


RESEARCHES  IN  STELLAR  PHOTOMETRY. 


With  one  exception,  the  range  in  either  series  does  not  exceed  0.4  magni- 
tude, a  rather  slender  basis  to  prove  variability,  thus  throwing  the  burden  of 
proof  on  the  first  observation  in  Hagen's  series.  But  this  is  not  confirmed  by 
the  nearly  simultaneous  observations  by  Williams,  so  that  the  matter  is  left  in 
doubt.  An  idea  of  the  color  of  the  stars  can  be  obtained  from  the  following 
summary  of  visual  and  photographic  results.  The  visual  magnitudes  are  photo- 
metric, the  photographic  are  from  a  Seed  27  plate  and  a  Cramer  isochromatic 
plate. 


Star. 

Vis. 

Seed. 

ISO. 

a 

9-i5 

9.  12 

9-13 

0 

8-93 

8-95 

8.95 

b 

9-53 

9-53 

9-53 

g, 

11.05 

11.05 

11.05 

i 

10.  12 

9.58 

9.70 

c 

9.28 

9.80 

9.66 

The  stars  a,  o,  b,  and  g,  with  their  visual  magnitudes,  were  used  as  standards 
from  which  to  obtain  the  photographic  magnitudes  of  /  and  c.  It  will  be  noticed 
that  the  star  c  is  shown  to  be  yellow  as  its  photographic  magnitude  is  0.4  to  0.5 
fainter  than  the  visual,  while  the  star  /  is  blue,  photographing  0.4  or  0.5  brighter 
than  the  visual  magnitude.  This  is  confirmed  by  the  visual  observations  of  Hagen 
and  the  writer,  compared  with  the  photographic  results  of  Williams. 


TABLE  24.— W  ANDROMEDA.     STANDARD  MAGNITUDE  STARS. 


1900. 

Magnitude. 

Residuals. 

Star. 

B.  D.  No. 

R  A 

Color 
P.  DM. 

Catalogue. 

Measured. 

From  Cats. 

3 
Nights 

H.C.O- 

P.  DM. 

H. 

P. 

H. 

P. 

se. 

3 

h   m     s 

e           i 

D 

E 

+  42         480 
+  42         506 

2    O9    48 

2   16  31 

+  42  13-9 

+  43  03.6 

GW- 
GW- 

7.61 

7-44 

8.14 
7.92 

7-73 
7-44 

8.14 
7-85 

+  12 
0 

o 

-7 

±7 

±2 

r 

+  43     474 

2    15    H 

+  44  08.5 

GW 

6.96 

7.20 

6.85 

7.26 

—  II 

+  6 

±9 

Means  .... 

7-34 

7-75 

7-34 

7-75 

±   8 

±4 

±6 

TABLE  25. — COMPARISON  STARS  IN  B.  D.  CATALOGUE. 


^tar 

B.  D. 

1855- 

B.  D. 

1855. 

No. 

Mag. 

R.  A. 

Dec. 

No. 

Mag. 

R.  A. 

Dec. 

° 

h  m   s 

0        / 

0 

h  m   « 

0       / 

a 

0 

b 
c 

+  43  457 
+  43  46o 
+  43  461 
+  43  462 

8.9 
9.0 
9-5 
9-5 

2  7  18 
2  7  Si 

2   8   21 

2  8  37 

+  43  45-6 
+  43  54-3 
+  43  41.6 

+  43  37-5 

r 
P 
1 

+  43  474 
+  43  478 
+  43  482 

6.5 
8.0 

8.2 

2   12  24 

2  12  53 

2   14  II 

+  43  56.o 
+  43  36.6 
+  43  43-1 

STELLAR    PHOTOMETRY. 


N 

ora 


•  « 


•  a 


b< 


r. 


u 


.  • 
•        * 


+  20' 


-+  10' 


•—  10 


-Spqle,  i 


1902  January  12 


R.  A. 


787  W  ANDROMED^E. 

"       * 

m  i4s.i.    Dec.  +43°  50'  26",  1900 


CHAPTER  IV.— W    ANDROMEDA. 


47 


TABLE  26. — COMPARISON  STARS  FOR  W  ANDROMEDA  (IN  ORDER  OP  RIGHT  ASCENSION). 


Star. 

Coordinates  from  Variable. 

Light 
Scale, 
Steps. 

Magnitude. 

R.  A. 

Dec. 

Measured. 

From  Curve. 

H. 

P. 

H. 

P. 

H 

s 

It 

a 

-721 

-   66.6 

+  468 

37-8 

9  15 

9-56 





n 

-421 

-   38-9 

-    131 

21.8 

ii  .09 

11.50 

d 

-387 

-   35-8 

-     15 

25.8 

10.61 

II  .02 

0 

-366 

-    33-8 

+  1007 

42.0 

8-93 

9-34 





I 

—  ^41 

—    31  .5 

—    238 

m 

Of 

-330 

-   3i-4 

+    «39 

19.9 

.  .   .   .   , 



I  I  .  21 

II  .62 

k 

—  Tl6 

—     29.  2 

—     2^S 

h 

o  *w 

-173 

—    16.0 

OJ 
-     229 

15  9 

11.80 

12.21 

y 

-117 

-    10.8 

-     44 

2.5 

13.61 

14.02 

x 

—  n6 

—    10.  7 

—     26 

w 

-    7i 

-     6.6 

-     3i 

12.95 

13-36 

..... 

ft 

-   63 

-      5-8 

+       22 

14.2 

14.6 

a 

-   60 

-     5-5 

8 

o 



13.58 

13  99 

6 

-   5i 

-     4-7 

+    206 

34-4 

9-53 

9-94 





Y 

-   3i 

-     2.9 

+     '3 

14-55 

14.96 

U 

-     9 

-     o.g 

—    129 

'9-8 

12.42 

12.83 

Z 

+   59 

+      5-5 

-     84 

i-5 

13-34 

'3-75 



c 

+  130 

+     12.  0 

+       9 

34-7 

9.28 

9.69 

g 

+  183 

+     16.9 

-    188 

2O.  2 

11.05 

11.46 





/ 

+  402 

+     37-1 

-     43 

29-3 

IO.  12 

10.53 



r 

+  240 

+  1140 

54-2 

6.85 

7.26 



P 

+  269 

-      70 

46-5 

7-89 

8.30 

9 

+  346 

+   320 

48-5 

7.67 

8.08 





TABLE  27. — 787  W  ANDROMED/B.    PHOTOMETER  MEASURES  OP  COMPARISON  STARS. 


1903  December  6.                                             6-INCH.                              Good;  moon  rising  at  end. 

Sidereal 
Time.1 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

"h    m 
23  23 

23  52 

O 

30 
3' 

26 

D 
E 

rai 

1 

P 

c 
b 
a 

0 

o 
a 
b 
c 
rai 
E 
D 

13.8  14.1   14.1 

12.3    12.0    12.2 

14.0  13.2  13.7 
14.4  13.9  14.2 
15.2  15-3  15-8 
25.1  26.0  25.9 
27.2  27.8  27.7 
24.2  25.7  25.8 
25.0  25.8  25.6 
25.3  24.3  25.5 
26.2  26.  I  25.5 
29.0  28.8  29.8 
27.9  28.7  28.0 
14.0  14.4  13.7 

12.2     12.4    II.9 

14.3  14.1   14  o 

14.00 
12.17 

13-63 
14.17 
IS  43 
25-67 
27-57 
25-23 
25.47 
25-03 
25-93 
29.20 
28.20 
14-03 
12.17 

14-13 

14.07 
12.17 

13-83 

0.81 
0.52 
0.76 
0.82 
i  .00 

2-34 
2.50 

2.  2O 
2.16 

7.70 
7.41 
7-65 
7-7i 
7.89 

9-23 
9  39 
9.09 

9-05 

8.  ii 

7.82 
8.06 

8.12 

8.30 
9.64 
9.80 
9  50 
9.46 

26.94 
28.39 
25-58 
25-25 

48  RESEARCHES  IN  STELLAR  PHOTOMETRY. 

TABLE  27. — 787  W  ANDROMEDA.    PHOTOMETER  MEASURES  OF  COMPARISON  STARS. — Continued. 


1903  December  21.                                                 6-INCH.                                                          Good. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings- 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6- 

H. 

P. 

h   m 
o  38 

i   18 

O 

15 
13 

10 

D 
E 

q 

p 

rai 
f 
c 

V 

b 
a 

0 
0 

a 
b 
c 
rar 
P 

i 
D 

12.3  12.3  it.  8 
9.8  10.4  10.0 
12.7  13.2  13.6 
15.3  14.8  14.4 
ii  .8  12.  i   11.7 

32.3  32.7  32.4 

27.1  26.9  26.7 
41  .0  42.  I  42.0 
28.1  28.0  27.8 
24.3  24.8  24.9 
23-2  23.7  23.9 

21.8    22.  I     22.8 
24.9    24.9    25.0 
27.3    27.9    28.0 
26.5    27.  I     26.7 
14.0    13.6    13.3 
14.2    15.2    14.5 

12.8  12.3  12.7 
11.4   10.7   II  .  I 
13.2   12.8  13.4 

12.13 
10.07 
I3-I7 
I4-83 
11.87 

32-47 
26.90 
41.70 

27-97 
24.67 
23.60 
22.23 
24-93 
27-73 
26.77 

13-63 
14-63 
12.60 
ii  .07 
I3-I3 

12.53 

10.57 
12.89 

H-73 
12.75 

0-57 
o-35 
0.62 
0.90 
0.61 

2-99 
2.32 
4.00 
2-44 

2.  12 
I.9I 

7-65 
7-43 
7.70 
7.98 
7.69 
10.07 
9.40 
11.08 
9-52 
9.  20 
8.99 

8.06 
7.84 
8.  ii 

8-39 
8.10 
10.48 
9.81 
11.49 

9-93 
9.61 

9.40 

26.84 

27.85 
24.80 
22.92 

1904  October  30.                                                                                                                  Quiet,  dull. 

22    48 

23  17 

37 
35 

33 

o 
a 
b 
c 
r 
P 

9E 
D 
D 
E 
1 
P 
r 
c 
b 
a 

0 

27.  I  28.0  27.3 
30.7  30.2  30.0 
32.0  32.9  33.0 
31.1  31.7  31.1 

10.8    IO.I    IO.2 

18.7  19.5  19.6 
16.3  17.7  17.3 

17.0  17.1    17.1 
19.1   19.6  19.9 
18.2  18.4  19.0 
IS-'   15-7   «5-8 
15.0  16.2  15.9 
18.1   18.5  19.1 
ii  .0  11.3  ii  .  i 
30.9  31.4  31.8 
32.7  32.9  32.7 
30.0  29.7  30.2 
29.0  27.8  28.3 

27.60 
30-30 
32-63 
3I-30 
10.37 
19.27 
17.10 
17.07 
19-53 
18-53 
15-53 
I5-70 
18.57 
11.13 
31-37 
32-77 
29.97 

28.37 

27.99 

30.14 
32.70 

31-34 
10.75 
18.92 
16.40 
16.30 
19.03 

2.56 

2-73 
3  .02 

2.84 
0.36 

i-47 
1.14 

I  .  12 

1.48 

8.91 
9.08 

9-37 
9.19 
6.71 
7.82 
7-49 
7-47 
7-83 

9-32 
9-49 
9.78 
9.60 
7.12 
8.23 
7.90 
7.88 
8.24 

1903  November  17.                                       12-INCH.                                                                    Good. 

23  36 
o    3 

28 
23 

0 

a 
b 
c 

f 
P 

?<H 
?OI 
fa 

f, 
C 

C 
b 

a 
o 

18.4  17.3  17.7 
19.0  19.4  18.7 
23.2  24.6  24.1 
21.4  21.6  21.7 

38.1  38.6  38.0 
27.5  28.6  28.4 
10.0  10.3  10.4 
15.0  14.8  14.3 
16.7  15-7  15-9 

16.  i   16.5  17.1 

IO.2    II.  I    10.4 

28.2  29.0  29.5 

38.8  38.0  37.9 

20.  o  20.4  20.7 

23-7  23.1  23.2 

18.9  18.8  19.7 
17.8  18.7  17.7 

17.80 
19.03 
23-97 
21-57 
38-23 
28.  17 
10.23 
14.70 
16.  10 

i6.57 
10.57 
28.90 
38.23 
20.37 
23-33 
I9-I3 
18.07 

17-94 
19.08 
23-65 
20.97 
38-23 

28.54 
10.40 

15-4° 

1.44 
I.  60 
2.08 

1.  80 
3-57 
2.51 
0.48 

I.IO 

8.88 
9.04 

9-52 
9.24 
ii  .01 

9-95 
7.92 

8-54 

9-29 
9-45 
9-93 
9.66 
ii  .42 
10.36 
8-33 
8-95 

CHAPTER   IV.' — W   ANDROMEDA.  49 

TABLE  27. — 787  W  ANDROMEDA.     PHOTOMETER  MEASURES  OF  COMPARISON  STARS. — Continued. 


1903  November  18.                                        12-INCH.                                                                  Good. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

p. 

h    m 

22    40 

23     3 

0 

37 
33 

0 

a 
b 
c 
g 

P 
1 
(fai 

? 

g 
C 

b 

a 
o 

19.9  20.9  20.  o 
22.  i   22.9  22.  7 
26.5  27.2  26.9 
22.7  23.8  23.4 
39-7  40.7  40.0 
31.9  32.1  32.7 

II  .0    12.  I     II  .  2 

9-7     9-3     9-2 
16.1   15.8   16.3 
10.7   ii.  o  10.6 
31.0  32.0  31.7 
39.2  40.0  39.6 

21.8    22.6    22.  I 
24.3    24.8    24.8 

19.6  20.  o  19.5 

18.3    19.  I     18.9 

20.27 
22.57 
26.87 
23  30 
40.13 
32-23 
"-43 
9.40 
16.07 
10.77 

31-57 
39.60 

22.  17 

24-63 
19.70 

18.77 

I9-52 

21  .  14 

25-75 
22.74 

39-87 
31-95 
II  .  IO 
9.24 

1-65 
1.83 
2.26 

2.OO 

3-75 
2.85 
0.56 
o.37 

I  .  21 

8.96 
9.14 
9-57 
9-31 
ii  .06 
10.  16 
7.87 
7.68 
8.52 

9-37 
9-55 
9.98 
9.72 
11.47 
10.57 
8.28 
8.09 
8-93 

1903  November  19.                                                                                                                       Very  good. 

22  24 
22  44 

39 
36 

o 
a 
b 
c 

f 

P 
9ot 
gai 

1 

6 
c 
b 
a 

0 

18.4  18.6   18.4 

21.8    21  .0    21.7 

22.9  24.0  23.5 

21.3    22.3    22.2 

37-9  39-0  38.7 
32.0  31.1  31.2 
9.8     9.8  10.0 
14.0  15.0  15.0 
15.0  14.3  15.1 

9.3  10.3  ii.  o 

32.0  31.0  31.7 

39-2  38.7  39-2 
20  .  2  21.9  20  .  8 

22.9  23.9  23.6 

19.8    21  .6    21  .  I 

18.2  18.5  18.1 

18.47 
21.50 

23-47 
21.93 

38-53 
31-43 
9.87 
14.67 
14.80 
10.20 
31-57 
39-03 
20.97 
23-47 
20.83 
18.27 

18.37 
21.17 

23-47 

21-45 
38.78 
3i  50 
10.04 

14-74 

1.50 

1.83 
2.06 

1.86 

3-64 
2.80 

0-45 
1  .02 

8.90 

9-23 
9.46 
9.  26 
ii  .04 
10.  20 
7-85 
8.42 

9-31 
9.64 
9.87 
9.67 

"•45 
10.  61 
8.26 
8.83 

1902  November  7.                                          40-INCH                                                     Fair,  uniform. 

6  20 

/ 
g 
Cos 
bm 

z 
u 

W 

\ 

V 

\y 

W 

u 

M 

Cat 

f 

12.  I    12.7    13.6 

21.7  22.5  24.2 
18.2  19.8  18.8 

21.2    21.4    21.8 

40.7  41.8  41.3 

34-8  35-7  34-3 
39-'  38.9  38.9 
44.0  45.6  44.0 

53-2  54-i  54  o 
33-8  33-2  32-9 
44.2  45.0  45.8 
38-5  39-5  40-0 
32.2  32.8  33.7 
42.9  42.5  42.6 

22.8    21.8    22.  O 

18.3  19.2  19.5 

23.0    22-3    22.8 
13.2    15.0    15.0 

12.80 
22.80 
18.93 

21-47 
41.27 

34-93 
38.97 
44-53 
53-77 
33-30 
45.00 

39-33 
32.90 
42.67 

22.  20 
I9.OO 
22.70 
14.40 

13.60 

22.75 
18.97 
21.84 
41-97 
33-92 
39-  «5 
44-77 

0.86 

2.OO 

i-57 
1.91 

3-99 
3-o6 
3-68 
4-30 

5-H 
3-00 

IO.  12 
II  .26 
10.83 
11.17 

"3-25 

12.32 
12.94 
13-56 
14.40 

12.26 

10.53 
ii  .67 
ii  .24 
11.58 
13-66 
12.73 
13  35 
>3-97 
14.81 
12.67 

50  RESEARCHES   IN    STELLAR  PHOTOMETRY. 

TABLE  27. — 787  W  ANDROMEDA.     PHOTOMETER  MEASURES  OF  COMPARISON  STARS. — Continued. 


1902  December  26.                                          40-INCH.                            Clear;  somewhat  unsteady. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

It    m 
5  50 

O 

/ 
g 

Cai 

ba- 
il 

TV 

y 

u 

z 
b<u 
Cai 

f 

15.0  15.8  17.0 
24.8  24.7  26.3 
20.  o  21.4  21  .6 
22.4  23.8  22.9 
20.9  20.9  21  .6 

42.3  41.9  41-4 

46.7  47-3  47-9 
37.7  38.8  38.2 
46.2  46.0  45.9 
22.3  23.4  24.8 

24.5    22.8    23.8 
24.2    24.8    25.8 

16.0  17.8  16.2 

15-95 
25-27 

21  .OO 

23-03 
21.13 
41.87 
47-30 
38.23 
46.03 
23.50 
23.70 

24-93 
16.67 

16.31 
25.10 

22.35 
23.27 

1.23 

2.21 
I  .96 
2.05 
1.84 
3-97 

4-54 
3-57 
4-44 

IO.2I 
II  .  IQ 
10.94 
11.03 
10.82 
12.95 
13-52 
12.55 
13-42 

10.62 
ii  .60 
ii-35 
"•44 
11.23 

13-36 
13-93 
12.96 

13-83 

1905  January  31.                                                                                                                           Good. 

5  30 

5  50 

39 

/ 
g 
Cai 

6ai 

V 
X 

•w 

y 

u 

2 
Z 
U 

y 

w 
\ 

V 

6«, 

Cai 

I 

10.7  10.9  ii.  o 
19.1  20.  6  19.7 
5-6     6.8     7.5 
9.7     9.2     8.6 
29.8  30.4  30.2 
53-5  53-9  53-4 
35-3  36.2  36.4 
41-5  43-5  42-3 
29.9  29.8  29.6 
38.0  38.2  38.5 
39-8  39-o  39-0 
30.0  30.6  31.1 
42.1  41.7  42.1 
35-2  35-3  35-i 
49-5  5'-7  5i.o 
29-7  3i-o  30-3 
11.5  10.8  12.7 
6.1     7.2     8.5 

2O.  O    21.  O    2O.  O 
12.  I     II  .2    II.3 

17.8  18.1   17.8 

10.87 
19.80 
6.63 
9-17 
30.13 
53-60 

35-97 
42-43 
29-77 
38.23 
39-27 
30-57 
41-97 
35-20 

50.73 
30.33 
ii  .67 
7.27 
20.33 

"•53 
17.90 

ii  .20 
20.06 

6-95 
10.42 
30.23 
52.16 
35.58 
42.20 
30.17 
38-75 

0.57 
1.72 
o.  16 
0.49 
2.67 
5-00 

3-25 
4.02 
2.67 
3-63 

ii.  3' 

ii  .46 
9.90 
10.23 
12.41 

14-74 
12.99 
13-76 
12.41 
13-37 

10.  72 
11.87 
10.31 
10.64 
12.82 
15-15 
13-4° 
14.17 
12.82 
13-78 

CHAPTER    IV. — W   ANDROMEDA. 


TABLE  28. — 787  W  ANDROMEDA.    CONSTANTS  FOR  REDUCTION  AND  COMPARISON  WITH  CATALOGUE 

MAGNITUDES. 


6-INCH. 

1903  December  6.                         1903 

December  21.                            1904  October  30. 

Star.                 Obs.  Mag.          4  Mag.                   Obs 

.  Mag.        J  Mag.                     Obs.  Mag.        4  Mag. 

C-        H.        P.        H.        P.           '         H. 

P.       H.        P.                   H.        P.       H.         P. 

£)  0.81     7.  70    8.  II  +.09—  .03      0.57    7.6 

5     8.06  +  .04  —  .08     1.48     7.83     8.24  +  .22  +  .  IO 

3    7.84—  .01—  .08    1.  12    7.47    7.88  +  .03  —  .04 
4    7-35--°2+-I5    0.36    6.71    7.12  -.25  -  .08 

E                    O    ^2     7    41      7    82  —    O3  —     IO       O    "JS     7    4 

f       .  .            OOI     6.90     7.31—.  O6  +.11'  —  0.14     6.9 

Means..    0.45    7.34    7.  75  ±.  06  ±  .  08      0.26    7.3 
M,  6.89    7.30]      7.0 

4    7-75  ±-02  ±.  10    0.99    7.34    7.  75  ±.17  ±.07 
8    7.49      6.35    6.76      

12-INCH. 

40-INCH. 

„.                 Mae.    .                       C" 

„                     May.                                        C> 

6-mcn.  Nov.  i7.  Nov.  I&    Nov.  19. 

i2-mch.      Nov.  7.       Dec.  26.      Jan.  31. 

o               .  .    8.98        i  44          i  65          i  50           I 

'..                                          QC7                        OIO                       O."^                O^^ 

a   9.12        i  60          i  83          i  .  83           c 

928        —  0,15            0.24        —  o  68 

i>  .             .    7.00       0.48         o.  s6         O.4S           / 

IOI2                 O.S6                  1-23                 O57 

q                     7  63       o  26         o  37         o  18           6 

Mean  C  o  95          i   10          I   20           1 

lean  C                                0.72            i  .00            o  32 

Mean  Mag.    8.41        8.41          8.41          8.41           ] 
M0  7.46          7.31          7.42           ^ 

lean  Mag.     10.00          10.00          10.00          10.00 
10  9.28            9.00            9.68 

MAGNITUOC 

H              is               12               n                10               9                a                7 

SO  

::::::::::::::::::::::;gj:::::  ::.::._::: 

t\  i  '.". 

"    -  787  W  ANDROMEPA  E         ; 

•  ~~     f' 

-__^  1  L^  

::::ffS  ::::;;::+:::::::::::::::;:::: 

J0r|5  -  :::::;i 

* 

A.                                               1  1- 

S                                                             2'ir 

c    :::~  ::::;::  -  .......".......  ,i.Z..... 

In                                                                                          . 

<"                                                                                  7  •  J 

10  —  :i::.;  F-*!-'  

;±S::  : 

"3-  -C 

^<xr 

:  zip.  .4:  ^:;n±^g+  ..:....:::::: 

—  |  —  t  —  ±  :::;;::::::  ::  —  |  — 

»:::::::::::::  jiiii::  :::::::  ::::::: 

:::::::|r!Eg:::|:::±::::::::::::::: 

:::S«sE:: 

,:::::»::::::::::::::::::  ::::: 

:;i!s?::±::::  :::::::::::  ^  

FIG    10. — MAGNITUDE-CURVE  FOR  W  ANDROMEDA. 


RESEARCHES   IN    STELLAR    PHOTOMETRY. 

TABLE  29. — 787  W  ANDROMEDA.     MEAN  MAGNITUDES. 


6-INCH. 

Star. 

December  6. 

December  21. 

October  30.                        Mean. 

Mag. 

J  Mag. 

Mag. 

J  Mag. 

Mag. 

4  Mag. 

Mag.H. 

Wag.  P. 

J  Mag. 

D 
E 

r 

a 
b 
c 

0 

P 

1 

7.70 
7.41 
6.90 

Mean.. 

9.09 
9-39 
9.23 
9-05 
7.89 
7-71 

Mean.. 

-0.03 
-0.03 
+  0.05 

7-65 
7-43 
6.94 

-0.08 

—  O.OI 

+  o  09 

7-83 
7-47 
6.71 

4-o.  10 
4-0.03 
—  o.  14 

7-73 
7-44 
6.85 

8.14 

7-85 
7.26 

±0.07 
±0.02 
±0.09 

7-34 

7-75 

±0.06 

—  o  .  03 
—  0.04 
—  0.04 
+  0.07 

—  O.OI 

+0.08 

9.20 
9-52 
9.40 
8.99 
7.98 
7.70 

+  0.08 
+  0.09 
+  o.  13 

+  O.OI 

4-0.08 
4-0.07 

9.08 

9-37 
9.19 
8.91 
7.82 
7-49 

—  0.04 
—  0.06 
-0.08 
—  0.07 
—  0.08 
—  o.  14 

9.12 
9-43 
9-27 
8.98 
7.90 
7  63 

9-53 

9-84 
9.68 

9-39 
8.31 
8.04 

±0.05 
±0.06 
±0.08 
±0.05 
±0.06 

±O.  10 

8.72 

9-13 

±0.07 

12-INCH. 

Star. 

November  17. 

November  18. 

November  19. 

Mean. 

Mag. 

J  Mag. 

Mag. 

J  Mag. 

Mag. 

J  Mag. 

Mag.  H. 

Mag.  P. 

J  Mag. 

0 

a 
P 
1 

b 
c 
f 
g 

8.90 
9.06 

7-94 

7-72 

Mean.. 

9-54 
9.26 

9-97 
11.03 

Mean.. 

+  0.03 

—  O.  IO 

+0.05 
+0.05 

8.96 
9.14 

7.87 
7.68 

4-0.05 
o.oo 

—  O.O2 

4-0.01 

8.92 
9-25 

7-87 
7.60 

—  O.OI 

4-o.  10 

—  O.O2 

—  0.07 

8-93 
9  i5 
7.89 
7.67 

9-34 
9-56 
8-30 
8.08 

±0.03 
±0.07 
±0.03 
±0.04 

8.41 

8.82 

±0.04 

-t-O.OI 
—  O.O2 
-0.15 
—  O.O2 

9-57 
9  3' 
10.  16 
ii  .06 

+  0.04 
4-0.03 
4-0.04 
4-o.  01 

9.48 
9.28 

IO.22 
II.  O6 

—0.05 
o.oo 
4-o.  10 
4-0.01 

9-53 
9.28 

IO.  12 

11.05 

9-94 
9.69 

10.53 
ii  .46 

±0.03 
±0.02 

±0.10 

±0.01 

IO.OO 

10.41 

±0.04 

40-INCH. 

Star. 

November  7. 

December  26. 

January  31. 

Mean. 

Mag. 

J  Mag. 

Mag. 

J  Mag. 

Mag.       4  Mag. 

Mag.  H.  Mag.  P.    A  Mag. 

6 
c 

i 
g 

u 

W 

y 

z 
1 

9-47 
9-i3 
10.  14 
11.28 

Mean. 

12.34 
12.96 
I3-58 
13-27 
14.42 

Mean. 

+  0.09 

+  O.OI 

—  0.07 

—  O.O2 

9-33 
9.24 
10.23 

I  I  .  21 

-0.05 

+  O.  12 
4-O.O2 

—  0.09 

9-33 
9.00 
10.25 
11.40 

—  0.05 

—  O.  12 

4-0.04 
4-o.  10 

9  38 
9.12 

IO.21 
11-30 

9-79 
9-53 
10.62 
11.71 

±0.06 
±0.08 
±0.04 
±0.07 

IO.OO 

10.41 

±0.06 

—  0.08 
+  O.OI 

—  0.03 
—  0.07 

-0.13 

12-57 

12-97 
13-54 
13-44 

4-0.  15 
4-0.02 
—  0.07 
4-o.  10 

12-35 
12.93 

I3-70 
I3-3I 
14.68 

—  0.07 

—  O.O2 

4-0.09 
-0.03 
4-0.13 

12.42 
12.95 
13.61 
13-34 
H-55 

12.83 
I3-36 
14.02 

13-75 
14.96 

±0.10 
±0.02 
±0.06 
±0.07 

(0.13) 

±0.06 

CHAPTER   IV. — W   ANDROMEDA. 


53 


TABLE  30. — 787  W  ANDROMEDA.    VISUAL  OBSERVATIONS  OP  THE  VARIABLE. 


No 

Date. 

tH 

g 

Aperture. 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing. 

t. 

A  Mag. 

Month 
and  Day 

Hour 
C.S.T 

Julian 
Day, 
G.  M.  T. 

Steps. 

Mag. 

i 

2 

3 
4 
5 
6 

7 
8 

9 
10 
ii 

12 
'3 
14 
15 

16 

17 

18 

19 
20 

21 
22 

23 
24 

25 
26 

27 
28 
29 

30 

3i 
32 
33 

34 

35 
36 
37 
38 

39 

40 

4i 
42 
43 

44 

45 
46 

47 

1899 
Feb.     6 
15 
24 
28 
Mar.     6 

13 
18 
28 
Apr.     4 

12 

May   21 
June  10 

July     5 
29 
Aug.   10 
30 
Sept.    4 
13 
25 

Oct.        2 

18 

23 
28 
Nov.    4 

'5 
26 
Dec.     4 
'9 
23 
29 

1900 
Jan.      4 

22 
31 

Feb.    1  6 

25 
Mar.     9 

22 

3' 
Apr.   17 
May  20 
28 
June  19 
July   25 

Aug.  29 

Oct.     4 
25 

1901 
Feb.  9 

7 
7 
7 
8 
8 
8 
8 
8 
8 
8 
15 
15 
15 
10 

9 
9 
9 

8 

7 
8 

7 
7 

7 
8 

7 

7 
7 
7 
7 
7 

7 
7 
7 

7 
8 
7 
7 
8 

9 
>4 
'4 
14 
15 

'5 

8 
7 

7 

2410000+ 
4692  .  54 
47°i  •  54 
4710.54 
47I4-56 
4720.56 
4727-56 
4732-56 
4742.56 
4749-56 
4757-56 
4796.88 
4816.88 
4841.88 
4865.67 

4877-63 
4897  .  63 
4902.61 
4911.58 
4923-54 
4930.58 
4946  54 

4951-54  j 

4956.54 
4963  •  56 

4974-54 

4985  -  52 
4993  •  54 
5008.54 
5012.54 
5018.54 

5024.54 
5042  .  54 
5051.52 

5067  .  54  | 

5076.58 
5088.54 
5«oi.54 
5»o.56  | 

5127.61 
5160.83 
5168.83 
5190.83 
5226.88 

5261.88 

5297-58 
5318.52 

5425-54 

80 
'SO 
'SO 
150 
'SO 
ISO 
'SO 
'SO 
'SO 
150 
'SO 

'50 

150 
'50 
'SO 
'50 
'SO 
150 
'50 
80 
40 
'50 
40 
40 

40 

40 
40 
40 
40 
40 

40 
40 
40 
40 
'50 
So 
'50 
So 
40 
'50 
'50 
'50 
275 
350 
460 

460 

237 
67 

40 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

6 

6 
6 
6 
6 
6 

6 

6 
6 
6 
6 

12 
6 
12 

6 

6 
6 
6 

12 

40 
40 

40 

40 

12 

6 

64-51;  ,  04-51;,  vf,  D3-4d,d5&. 
04-5-11,  /2i>,  Did,  -v  very  red 

d\—  J.D  /6l)  2)^—4(7 

29.9,  30.2,  29.3,  29... 
30.2,  27.3,  26.8 
22.3,  23.3,  23.7   . 

23-3,  25.8,  22.2  . 
22.3,  23.8,  22.2  . 
20.  8,  20.2,  21  .9  . 
18.3,  2O.  2,  20.9  . 

16.2,   16.9,   16.9   . 

29.7 
28.1 
23.1 

23-7 
22.7 
20.9 
19.8 
16.6 
14.4 
<i6 
<i6 
<'5 

<20 

<'4 
<i6 
16.8 
19.8 
21.3 

24-4 
24.6 

3'-9 
33-9 

36.5 
40.  i 

47-5 

48-5 
52.' 
47-8 
48.7 
47-9 

47-o 
46  5 
44.2 

36.8 

35-3 
30-3 
28.8 

24.7 

19.0 
<'5-9 

7-7 
6.1 
3-0 

3-6 

ii.  8 
'3-8 

45-2 

10.06 
10.31 
10.92 
10.88 
10.98 
ii  .20 
11.32 
11.71 
12.08 
<n.8 
<n.8 
<  ii  .9 
<"-3 

<  12.  O 

<n.8 
ii  .70 
11.32 
11.15 
10.78 
10.76 
9-85 
9.60 

9.40 
8.80 

7.84 

7.66 
7.16 
7.78 
7-76 

7-77 

7.89 
7  95 
8.27 

9.22 

9.42 
10.  06 
10.23 

10-73 
ii  .41 
<n.8 

12-73 
12.90 

'3-23 
13-18 
12.27 

I  2.  O2 

8.  II 

good 
moon 
fair 
good 
good 
good 
fair 
good 
fair 
fair 
fair 
good 
poor 
good 
fair 
fair 
fair 
fair 
fair 
good 
poor 

good 

good 
good 

fair 

good 
good 
good 
good 
good 

good 
good 
good 

good 

good 
good 
fair 

good 

low 
low 

o 

9 

18 

22 

28 

35 
40 
50 

57 

205 

2IO 

2I9 
231 
238 
254 
259 
264 
271 

282 

293 
301 
3'6 
320 
326 

332 
350 

359 
375 

384 
o 

'3 

22 

39 

80 

IO2 
138 

'73 

209 
230 

337 

+  0.08 
+  0.04 
+  0.31 
+  0.18 
+  0.03 

—  O.OI 

—  0.09 
—  0.04 

+  O.  IO 

—  0.07 

-0.31 

-0.35 
-0.15 
+0.13 
-0.03 

—  0.03 

+  O.  IO 
—0.09 

-0.28 
—  o.  19 

-0.54 
+0.23 
+0.08 

+  O.  IO 

+0.09 
-0.36 
-0.33 

+  O.IO 

—  0.04 
+0.04 
-0.17 

+0.03 
+  0.04 

+  o.  14 

+  O.O2 

+0.30 
+  0.70 

4-0.62 
+  0.07 

+  0.17 

/6i)  Tjd  v2g  

d~j—  SD  gii  vim  

(741),  77131)  DI/I  

v  not  seen,  limit  c  

D  not  seen  h  glimpsed  .  .  . 

D  not  seen,  limit  i  <  h  .... 

v  not  seen,  limit  m  

D  not  seen,  limit  2</i  ... 

"v  not  seen  limit  h  

J31;,  DO—  I  ft  

'7-2,  '6.4  

21.2,     18.4,     19.8     . 
21.2,   2O.9,  21.8,    21.; 
24-3.    23.9,    24.2    ... 
24.8,    24.4,    24.7     .  . 
30.4,    30.7,    34.8     .  . 

33-9,  34-4,  33-8  {. 
33-7,  33-9.  34-3  > 
35-7,  37-3  
37-7,  40-8,  42.0  .  . 
44.7,  46.8,  50.0  \ 
48  .  5,  47  .  5  > 

vig  vim  Tn  d^—^v 

di—2'v  1)4771  D4<7  

div,  1)4—  SOT,  1)4—  5<7  
641),  041;,  1)8—  lod  
CID    D&    ^4~5/           

CID  60—  ID  D5/  

Die,  ao-iD  

D3C,  D3O,  DO  

DIOC,  vga,  D8o  ±  ,  D2p,  qiv.  i 

D3p,  r6D,  D2g  
ro—  ID  D6p  .  . 

49-5,  46-2,  50-5  •  • 

ryv,  D2p  

T$V,  D3~  4p,  D6fl  
r4~  5D,  DI—  2p,  1l6o  

D6o,  D2-3P,  rSi>  

Dip,  D3-40  
D2p,  D2O,  
O5D,  O2D,  D2&,  D3C  
D2&,  D3C  
IJI-2D,  D&  

641),  D/,  D5-6d  
D/,  D2—  3d  
/4~  SD,  Did  

47-2,  48-5  
48.2,  50.0,  48.0 
47.7,  48.0,  48.0  .  . 

48  .  o,  49  .  o,  44  .  2 
47-5,  45-5  
44-5,  44-o  
37-0,    35.8,    36.4,]. 
37-7,  36.4,  37-7-  •  / 
36.3,  34-4  
30.4,  29.3,  31.3   .  . 
29-3,  28.3  
24.8,  26.8  > 

/5D  dlD,  D3?W  

24.3,  24.8,  22.9  f 
'9-2,  '8.9  

giv,  D3/i  
D  not  seen,  limit  h  

A8-IOD,  UO-IV,  V2W  

U2D,  viw,  D2J/,  limit  j/  
W2—  3D,  DI—  2z,  115—  6D,  vy... 

W&-8D,  tO  ID,  1)40,  V2Z,  VI-2y  •( 
1)2U  

6-9-.  9-3,  7-0  
7.8,  6.0,  4.5  

2-5,  3-o,  4-3  2.5   • 
2.8,  4.0,  4.0  .  .  .) 
3-5,  4-o  i 

moon 
fair 

moon 
good 

fair 

D4U,  tl2V  
pi—  2D,  D3~  40  

13-8,  '3-9  
45-0,  45.5  

54 


RESEARCHES  IN  STELLAR  PHOTOMETRY. 


TABLE  30. — 787  W  ANDROMEDA.     VISUAL  OBSERVATIONS  OF  THE  VARIABLE. — Continued. 


No. 

Date. 

y 

"3 

u 

O 

1 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing. 

• 

d  Mag. 

Month 
and  Day. 

Hour 
C.  S.  T. 

Julian 
Day, 
G.  M.  T. 

Steps. 

Mag. 

48 

49 
50 
51 
52 
53 
54 
55 
56 

57 
58 
59 
60 
61 
62 

63 

64 
65 
66 

67 
68 
69 

70 

71 
72 
73 
74 
75 
76 
77 
78 
79 
80 

1901 
Nov.     i 

1902 
Jan.    12 
Feb.     4 
Mar.     4 

27 
Apri     2 
Oct.      i 
Nov.     7 
Dec.   26 

1903 
Oct.    1  1 

13 
Nov.  ii 
17 
Dec.     6 

21 
1904 

Jan.      8 
Aug.  29 
Oct.      6 
30 

1905 
Jan.    28 
Feb.     9 
25 
Mar.     3 

24 
Apr.      7 
June  13 
Aug.     9 
28 
Sept.  17 
Oct.      i 

20 

Dec.   23 
30 

7 

9 

7 
9 

IO 

7 
7 

8 
ii 
9 

9 

8 
8 

7 

7 
8 

15 
'5 
9 

8 

9 

8 

IO 

9 

2410000  + 
569°  54 

5762 
5785 
5813 
5836 
5842 
6023.63 
6061 
6110 

6399-54 
6401  .63 
6430 
6436.67 

6554-54 
6470.54 

6488.54 
6722.58 
6760.71 
6784.63 

6874.63 
6886.58 
6902  .  56 

6908  .  54  - 

6929.54 
6943-58 
7010.83 
7067.83 
7086  .  64 
7106.58 
7120.63 

7137-54 
7203.70 

7210.63 

275 

237 
67 
67 
67 
237 
237 
237 

150 
80 
67 
67 
40 
40 

67 
15° 
40 

450 

237 
275 
237 
67 

275 
150 
40 
20 
15° 
150 
150 
237 
80 

237 
237 

12 

24 
40 
12 
12 
12 
40 
40 
40 

6 

12 
12 

12 

6 
6 

12 

6 
6 
40 

40 

12 
40 
12 
12 
6 
6 

5 
6 
6 
6 
40 

12 
40 

40 

(vh,  V4U    ) 

ic   o.    1-2   8  .  . 

14.8 

ii  .92 

good 

206 

278 
301 
329 
352 

+  0.18 

-0.63 
—  0.61 

-limit     3-4  <u,  or  2  <  10,  S 
(         or  2<x                     ) 

photograph                 

•v  very  bright  and  very  red 
photometer  

7.8 
7.11 

7-75 

photometer  

photometer  

112-311,  ii2-yw  
photometer   

7-3,  7-5  

7-4 

12.77 

12.  24 
I0.8O 

<I2.5 
12.72 

12.88 
12.66 
11.71 
11.08 

10.80 
11.63 
<n.8 
13-I9 

12.05 

<I2.5 
11-50 

II  .70 
10.80 
9.SI 

7-95± 
10.  71 
10.94 

11-73 
12.15 

12-33 
13.81 

13-88 

poor 

good 
good 
good 
good 
good 
good 

good 
fair 
fine 
good 

good 
poor 
good 

good 

fair 
good 
good 
good 
fair 
fair 
fair 
good 
fair 

good 

'43 
181 
230 

123 
125 
154 
1  60 
178 
194 

212 
50 

88 

112 

2O  2 
214 
230 

236 

257 
271 
338 
0 

18 
38 
52 
69 
135 
142 

-0.13 

—  O.  IO 

-0.15 
-0.27 

+  O.  IO 

—  0.04 
-0.68 
-0.97 

-0.79 

—  O.  12 
+  0.24 

+  O.2O 

+  O.6O 
+  I  .00 
+  I.I5 

+0-73 
+  0.23 
+  0.81 

+  0-34 
+  0.38 
+  0.30 
o.oo 
4-0.82 

+  0.92 

photometer  

11  not  seen  limit  u  

7-7 
6-3 
8.4 
16.6 

uiv,  7/42  

88,    s   S  .  . 

photometer   also  1*3—41'.  .  .  . 

photometer,  also  uiv,  v6z. 
photometer,  also  g4v,  nih.  . 

8  8    7   s 

16.2,   16.9  

26.8,   21.7  

24.2 
17-2 

3-5 

v  not  seen   limit  h  

win    v\*.  .                        ... 

A    O      T.    O 

photometer  

•a  not  seen,  u  glimpsed  .  . 

g(>ii,  v2h,  C2b  
w,x,y  and  z  seen,  a  glimpsec 

cm  vib,  i>5/  

Is.  3 
16.7 
24.2 
34-5 
46-5 
25-0 
23.1 
16.5 

12.8 
II  .2 

—  2.2 

-2.9 

20.  2,    14.  2,    18.4    .  . 
14-2,    17-9  I 

24-8,    23.7  

33-7,  35-4,  34-3  

(3—411,  i>4g,  C2~3b  

d2—3V,  V2<J,  /5~-  67?,  C2&  

04-51;,  vih  

h^V,    VI—  2U  

25-8,  24.2  

23.3,    22.2,     23.8     . 

15-7,   16.9  
ii.  9.   13-8  
10.9,   11.3  

—  I  .  O,    —  2  .  O,    —  5.O 

-s'-o3                  / 

Z4.V     n  "\V     V^B,    V^y  •  

CHAPTER   IV. — W    ANDROMEDA. 


55 


§ 


§ 


I 


1 
1 


S, 


FJO.  ii. — LIGHT-CURVE  OF  W  ANDROMEDA. 


RESEARCHES   IN   STELLAR  PHOTOMETRY. 
TABLE  31. — MEAN  MAGNITUDES  FROM  33  DAY  GROUPS. 


Group  No.  . 
T   D.  ., 

i 

-3-1 

2 

66 

3 

4 

5 
i6c 

6 

7 

8 

9 

IO 

ii 
iffi 

12 
inf. 

3°3 

f        t 

15 

46 

211 

24.6 

278 

Ti6 

380 

,     j      M 

IO.63 

11.58 

II  .39 

102^ 

8  42 

7  .    Q 

8  04 

Q    12 

4692j     JM 

+  o.  13 

—  O.OI 

—  O    24. 

—  O    O2 

—  O   O"* 

I  No. 

5 

4 

7 

r    « 

12 

39 

80 

I  O2 

M8 

17-3 

2  2O 

^7 

o«J       M 

to.  34 

ii  .41 

12    71 

12    QO 

1^2^ 

13   18 

12    14. 

8    II 

5°88i     JM 
I  No. 

f       < 

-0.03 
3 

+  0.04 

i 

+  o.  14 

I 

+  O.O2 

I 

+  0-30 
I 

+  0.70 

i 

+  0-34 
2 

2O6 

+  o.  17 

I 
^2Q 

o    J       M 

1  1    Q2 

5484      JM 

+  o   18 

—  O    6^ 

L  No. 

I 

I 

r    < 

14.  -7 

181 

230 

,   j       M 

12    77 

12    2J. 

10  80 

588°      JM 

—  O    1  1 

—  O    IO 

—  O    IS 

L  No. 

I 

I 

I 

r    * 

12*; 

i  <;7 

1  86 

212 

,„,!       M 

12    72 

12    77 

1  1    4.O 

to  80 

6276  i    JM 

—  O    27 

+  O.O^ 

—0.82 

—  O   70 

L  No. 

2 

2 

I 

r    < 

50 

112 

216 

fi,,,l       M 

ii  .63 

I"*.  10 

II  .78 

6672      JM 

—  O.  12 

-f  o.  24 

+  0.40 

L  No. 

I 

I 

2 

r    t 

Means      £ 
L  No. 

14 
10.48 
+  0.07 
8 

45 
"•54 

T-O.O2 

6 

80 

12-73 
+  o.  14 
i 

"3 
12.94 

o.oo 
3 

146 
12.92 
-1-0.06 

4 

1  80 

12.27 
-0.31 

4 

216 
11.47 
O.OO 
IO 

246 
10.25 

—  O.O2 

4 

278 
8.42 
—  0.12 

4 

327 
7.6O 
—  O.IO 

6 

350 
7.00 
—0.30 

4 

380 

9-32 
-f  0.03 

3 

TABLE  32.— 787  W  ANDROMEDA.    OBSERVED  MAXIMA  AND  MINIMA. 

Elements  of  maximum.      1899  Dec.  16  (J.  D.  2415005)+396'  E.     M  -  m=192d. 


MAXIMA. 

MINIMA. 

t" 

Date. 

Mag. 

j 

Date. 

Mag. 

Corr. 

Wt. 

1 

Corr. 

Wt. 

W 

Calendar. 

J.  D. 

H. 

P. 

W 

Calendar. 

J.  D. 

H. 

P. 

o 

1899  Dec.     7 

4996 

7.42 

7.83 

-   9 

27 

o 

1899  June  1  6 

4819 

13.0 

'3-4 

+   6 

20 

i 

1901  Jan.    15 

5400 

me 

—    i 

i 

i 

1900  July   23 

5224 

13-36 

13-77 

+  «5 

9 

2 

1902  Feb.   28 

5809 

7-4 

7.8 

+  12 

4 

2 

1901  Aug.  13 

5610 

me 

+   5 

i 

3 

1903  Mar.   1  6 

6190 

me 

-   3 

i 

3 

1902  Aug.  31 

5993 

13.0 

13-4 

-   8 

2 

4 

1904  Apr.    !7 

6588 

me 

—    i 

i 

4 

1903  Sept.  25 

6383 

13  o 

13-4 

—  14 

5 

5 

1904  Nov.  15 

6800 

13-34 

13-75 

+   7 

6 

CHAPTER   IV: — W    ANDROMEDA. 


57 


too 


DAYS 

ZOO  3OO  4OO 


500 


Max..  •    3/6 d 
Min.    m 
M-m* 


u 
Q 

I" 


FIG.  12. — MEAN  LIGHT-CURVE  OF  W  ANDROMEDA. 


CHAPTER  V. 

4315    R    COM^E. 
R.  A.   nh  sgm  8.45;  Dec.  +  19°  20'  19"    (1900). 

Disco veied  by  Schonfeld  in  1856,  this  might  almost  be  called  a  historic 
star,  but  the  published  observations  were  so  fragmentary  in  character  that  more 
work  was  needed.  The  period  was  found  to  be  only  a  few  days  less  than  a  year, 
and  the  maximum  so  near  conjunction  with  the  sun  that  cpmparisons  were  un- 
certain in  the  twilight,  while  the  beginning  of  the  descending  branch  of  the  light 
curve  was  lost  in  the  daylight,  and  it  appears  that  no  one  had  followed  it  in  the 
morning  sky,  or  continued  observations  through  the  minimum.  The  present 
observations,  when  combined  into  the  mean  curve,  figure  15,  cover  the  entire 
period,  and  seem  to  show  that  the  time  of  maximum  is  about  20  days  later  than  that 
found  from  evening  observations  alone.  The  maxima  numbered  40,  41,  42,  44, 
and  48  are  well  covered  with  observations  on  both  branches  of  the  curve,  but 
the  twilight  renders  it  difficult  to  fix  the  exact  magnitude  at  maximum;  it  can 
only  be  stated  as  about  8.5,  with  the  evidence  insufficient  to  say  whether  it  changes 
from  one  maximum  to  another.  The  minima,  on  the  contrary,  can  be  well  fol- 
lowed, the  three  best  observed,  numbers  44,  46,  and  49,  giving  a  magnitude  a 
few  tenths  brighter  than  14. 

The  faint  stars  with  the  Greek  letters,  z,  and  the  variable  were  connected 
with  the  bright  star  F  (B.  D.  +  19°  2526)  in  February  and  March,  1900,  with  the 
micrometer  on  the  4o-inch.  The  place  of  the  variable  given  above  results  from 
the  Berlin  A.  G.  Catalogue  position  of  the  star  F. 


431.5  R  COMM. 
TABLE  33. — STANDARD  MAGNITUDE  STARS. 


Star. 

B.  D.  No. 

1900. 

Color 
P.  DM. 

Magnitude. 

Residuals. 

R.  A. 

Dec. 

Catalogue. 

Measured. 

From  Cats. 

3 
Nights 
inter 
se. 

H.C.O. 

P.  DM. 

H. 

P. 

H. 

P. 

A 
B 
F 

0 

+  18  2539 
+  18  2546 
+  19  2526 

Mean  .  .  . 

h    m     s 
n  49  oo 
"   52  35 
it   58  57 

0               / 

+  18  43.4 
+  18  01.6 
+  19  23.1 

WG 
GW 
G- 

7.76 
6.91 

7.64 

8.16 

7.04 

8.02 

7.89 
6.81 
7.62 

8.19 
7.11 
7.92 

+  13 
—  10 

—     2 

+   3 
+   7 

—  10 

±  6 
±   7 
±   4 

7-44 

7-74 

7-44 

7-74 

±    8 

±   7 

±   6 

6o 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABLE  34. — 4315  R  COM^E.    COMPARISON  STARS  IN  B.  D.  CATALOGUE. 


B.  D. 

1855- 

B.  D. 

i855. 

Star. 

No. 

Mag. 

R.  A. 

Dec. 

No. 

Mag. 

R.  A. 

Dec. 

0 

k  m  s 

O       ' 

o 

h  m  s 

0       / 

V 

+  19  2522 

9i 

ii  54  2 

+  19  59-i 

W 

+  19  2525 

9-i 

ii  55  IS 

+  19  38.3 

a 

+  20  2670 

8.6 

"  54  58 

+  20  5.5 

P 

+  20  2676 

8.4 

ii  56  25 

+  20  I  I  .  8 

R 

+  19  2524 

8.8 

ii  55  9 

+  19  20.4 

H 

+  20  2683 

7.8 

ii  59  59 

+  20  IO.  1 

TABLE  35. — COMPARISON  STARS  FOR  R  COMJE. 


Star. 

Coordinates  from  Variable. 

Light 
Scale, 
Steps. 

Magnitude. 

R.  A. 

Dec. 

Measured. 

From  Curve. 

H. 

p. 

H. 

P. 

H 

s 

'/ 

V 

-2390 

-168.8 

+  '454 

9-77 

10.07 

a 

-I589 

-112.3 

+  1772 

40.9 

9.09 

9-39 

R 

-H54 

—  102.4 

—   900 

39-o 

9  15 

9-45 

lU 

-1328 

-    93-9 

+   289 

32.6 

10.  14 

10.44 

d 

-   453 

—    32.0 

-   329 

25-4 

10.67 

10.97 

b 

-   408 

-    28.8 

-   658 

17.1 

12.29 

12-59 

i 

-   404 

-    28.5 

+   735 

26.4 

10.57 

10.87 

c 

-   336 

-    23.7 

-    869 

18.6 

12.43 

12.73 

z 

-   379 

-    26.8 

+    124 

"•3 

12.83 

I3-I3 

P 

-   359 

-    25.4 

+  2160 

44.2 

'8^57 

8^87 

u 

-   289 

—    20.4 

—   609 

12.  8l 

13.11 

s 

-   281 

-    19.9 

-      34 

o 

14.70 

15.00 

a 

—   263 

-    18.6 

+      7i 

3-0 

14.08 

I4-38 

ft 

-   259 

-    18.3 

+   226 

4.0 

14.08 

14-38 

F 

-    199 

-    14.1 

+    13° 

52-9 

7.62 

7-92 

f 

-    138 

-     9-7 

+   273 

9.0 

13  19 

13-49 

7 

-    136 

-     9.6 

+    194 

4.0 

14.17 

H-47 

e 

+   327 

+   23.1 

+    171 

21.3 

"-47 

iJ-77 

e' 

+   352 

+    24.9 

+    185 

16.3 

12.  16 

12.46 

H 

+      190 

+  2058 

49-2 

7.98 

8.28 

TABLE  36. — 4315   R  COM^E.     PHOTOMETER  MEASURES  OP  COMPARISON  STARS. 


1904  July  4.                                                       6-INCH.                                                                   Fair. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

/;  m 

0 

16  14 

•v 

26.8  26.8  27.9 

27.17 

27.84 

2-44 

9-59 

9-89 

R 

27.9  28.6  28.7 

28.40 

27.60 

2.41 

9-56 

9.86 

59 

a 

25.4  24.8  24.9 

25-03 

23-65 

2.01 

9.  16 

9.46 

U 

27.  2    27.  I     28.2 

27.50 

27.  12 

2.36 

9-5i 

9.81 

60- 

Da, 

14.0    13.9    13.8 

13.90 

14.27 

0.83 

7.98 

8.28 

lU 

31.4    32.4    31.9 

31.90 

32-57 

3-00 

io.  15 

10.45 

F 

10.9    10.4    IO.7 

10.67 

II  .  19 

0.42 

7-57 

7-87 

Be, 

9.8  io.i  ii.  i 

10.33 

10.98 

0.38 

7-53 

7-83 

63 

A 

I4.I    14.7    14.3 

14-37 

14.29 

0.83 

7-98 

8.28 

A 

14.2    14.  O    144 

H2O 

63  + 

11.9  ii.  i   ii  9 

ii  .6^ 

62- 

F 

12.  O    II  .2    II.9 

ii  .70 

62  + 

iV 

7-1.8    12    O    11   O 

•*•*    2"* 

63 

Dal 

15.0  14.2  14  7 

14.  6^ 

63 

U 

26  .  4  26  9  26  9 

26    73 

63 

a 

22.2    22-3    22    3 

22.  27 

63 

R 

26.8  26.7  26  9 

26.80 

16  40 

64 

V 

27.8  29.4  28.3 

28.50 

STELLAR    PHOTOMETRY. 


N 
om 


PLATE   5. 


•x 


o 


10' 


20'  , 


Scale,  i  mni  =  I3".6. 


4315    R 
R.  A.'nh  5gm  35.4.     Dec.  +'19°  20'  19",  1900. 


1905  April  2$. ; 


CHAPTER  V. — R 


61 


TABLE  36. — 4315  R  COM,B.     PHOTOMETER  MEASURES  OF  COMPARISON  STARS. — Continued. 


1904  July  9.                                                       6-INCH.                                                                 Good. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

rtean  Scale  Readings. 

Magnitude. 

Scale  Readings. 

tfean  of  3. 

tfean  of  6. 

H. 

P. 

8.09 

7-97 
10.31 
9-58 

10.35 
7.92 

9  59 
9.28 
9.96 
8.00 

h    m 
15  54 

16  18 

57 
57 
56 

57- 

57- 

57 
58- 
58 

58 
58 
59 
60 
60- 
62- 
62 

A 
Bat 
tfo. 
R 
W 
F 

V 

a 
U 
DJI 

Dar 

U 
a 
F 
W 
R 
Bai 
A 

J3-7  '4-4  14-1 
13.2  13.  i   13.1 
33-3  33-5  34-0 
27.8  27.2  28.0 
35-i  35-o  34.9 
14.1   13.5  13.3 
27.3  28.2  27.7 
24.5  24.9  25.1 
31.4  31.9  31.2 
14.0  14.3  14.0 
14.0  14.5  14.8 

29-9  3°  3  30  7 
24.3  24.8  25.0 
12.7  14.8  13.9 

33-2  33-4  34-o 
26.8  28.2  27.8 
14.9  14.9  14.9 
15.6  15.7  16.0 

14.07 

13-13 
33  60 
27.67 
35-oo 
13  63 
27-73 
24.83 
3I-50 
14.  10 
14-43 
30  30 
24.70 
13.80 

33-53 
27.60 
14.90 
15-73 

14.90 
14.02 

0.92 
0.80 

3-'4 
2.41 

3-i8 
0.75 
2.42 

2.  II 

2-79 
0.83 

7-79 
7.67 

IO.OI 

9.28 
10.05 
7.62 

9-29 
8.98 
9.66 
7.70 

27-64 
34-27 
J3-72 

24-77 
30.90 
14.27 

1905  January  13.                                                                                                                           Good. 

12  24 

13     5 

D 
U 
a 
lU 

F 
d 
R 
B 
A 
A 
B 
R 
d 
F 
lU 
a 
U 
D 

9.1     9.2  10.0 
31.3  32.1  31.7 
28.  i  28.7  29.5 
36.8  36.1  36.7 
15.7   16.1    15.6 
48.2  47.2  47.9 

30.3  30.3  30.3 
8.9     8.8     8.4 
17.5  18.  i   18.  i 
17.7   17.7  18.1 
8.8     9.1     8.8 
28.7  29.7  29.4 
48.7  48.6  48.8 
17.  i   16.  i    17.0 
36.3  37-7  37-1 
29-2  30-3  30-6 
33-8  34-3  33-2 

10.5    II.5    II  .2 

9-43 
3I-70 
28.77 
36.53 
15.80 

47-77 
30-30 
8.70 
17.90 

17.83 
8.90 
29.27 
48.70 
i6.73 
37-03 
30.03 

33-77 
ii  .07 

10.25 

32.74 
29.40 
36.78 
16.26 
48.24 
29.78 
8.80 
17.86 

0.32 

3.02 
2.62 

3-55 

I.  12 

4-57 
2.66 
0.18 
i-33 

6.88 
9-58 
9.  18 

IO.  II 

7.68 

ii   13 

9.22 
6.74 
7.89 

7.18 
9.88 
9.48 
10.41 
7.98 
u-43 
9  52 
7.04 
8.  19 

1905  February  3.                                              U-INCH.                                                    Good,   -4°F. 

14     o 
14  43 

34 
45 

R 
lU 
c 
b 
d 
Fa- 

i 

a 
U 
U 
a 
P 

L 

d 
b 
c 
it' 
R 

13-0    13-5    14-0 
23.6    24.6    23.9 
46.5    46.5    46.3 
42.8    44.2    43.0 
31.0   31.9    31.3 
8.4      8.7      8.4 
26.7    27.0   26.9 

15-5   '5-7   '5-4 
21  .8  21.7  20.8 
19-3  '9-9  20.2 
13.8  13.9  14.4 
11.3   i  i  .  8   i  i  .  8 
27.7   29.4  28.6 
8.9     9-9     8.3 
27.8  28.2   28.9 

43-1   43-9  42-3 
44.0  44.6  43.8 
25.0  25.2   24.8 
17.0  16.  i   17.1 

I3-50 
24-03 
46.43 
43-33 
31.40 
8.50 
26.87 
15  53 
21-43 
19.80 
H  03 
ii  .63 
28  .  57 
9.03 
28.03 
43-23 
44-'3 
25.00 

i6.73 

15.12 

24-52 
45.28 
43.28 
29.72 
8.76 
27.72 
14.78 
20.62 

1.07 
2.16 
4-36 
4-13 
2.62 
0.31 

2-43 
i  .02 

'•77 

9.  10 
10.  19 
12-39 

12.  16 

10.65 

8-34 
10.46 
9  05 
9.80 

9.40 
10.49 
12.60 
12.46 

10-95 
8.64 
10.76 
9-35 

IO.  IO 

0.62 

8.65 

8-95 

RESEARCHES    IN    STELLAR    PHOTOMETRY. 


TABLE  36. — 4315  R  COM.B.     PHOTOMETER  MEASURES  OP  COMPARISON  STARS. — Continued. 


1905  February  27.                                              12-INCH.                                 Good,  a  little  unsteady. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings 

C. 

Magnitude. 

Mean  of  3 

Mean  of  6. 

H. 

P. 

h   m 
8   25 

8  50 

O 

R 

lU 
d 
c 
l> 
F0, 
/ 
a 

V 

u 

a 

Fa, 
6 
c 
d 
lU 
R 

18.3  19.0  19.  i 
27-7  28.3  27.5 
33-4  33-6  32.9 
48.9  47.8  48.7 
45.0  46.7  46.2 

12.2    12.4    12.3 
32.1    32.4    33.2 

15.6  16.9  16.0 

22.  O    22.8    23.0 
23.0    22.6    23.1 
16.7    16.9    I7.O 

31-0  33-2  32-1 
12.8  13.3  12.3 

47.8  47.6  46.9 

49  .  o  48  .  8  49  .  i 
32.0  32.0  32.1 
26.0  27.  i   26.3 
18.5  18.7  18.1 

18.80 
27-83 
33-30 

48.47 

45-97 
12.30 

32-57 
16.  17 
22.60 
22.90 
16.87 
32.10 

1  2.  So 

47-43 
48.97 
32-03 
26.47 
18.43 

18.62 

27-15 
32.66 
48.72 
46.70 
'2.55 
32.34 
16.54 
22.75 

1-55 
2.38 

2-93 
4.68 
4-50 
0-75 
2.89 
1.26 

2.OO 

9-29 

IO.  12 

10.67 
12.42 
12.24 
8.49 
10.63 
9.00 
9-74 

9-59 
10.42 
10.97 
12.72 

12.54 
8.79 
10.93 
9  30 
10.04 

1905  March  3.                                                                                                                               Good. 

9  45 
10  24 

4i 

R 
lU 
c 
b 
d 
Fa, 

a 
U 
U 
a 
t 
F0, 
d 
b 
c 
lU 
R 

'3-7   13-4  13-4 
23.3  23.0  22.8 
46  .  9  46  .  i  45  .  8 
45-5  45-o  45-6 
29.4  30.0  29.8 
9.7     8.9     8.9 
29.5  28.8  29.2 
15  9  16-3  15-9 

2O.  O   21.  I    2O.  I 

20  .  5  21.2  20  .  7 
16.0  16.8  16.6 
31.0  29.9  31.0 

IO.I       8.9    IO.I 

31.0  31.8  31.1 

47-7  48-4  47-3 
47-2  46.7  47-7 
25.0  26.2  25.7 
16.9  17.3  16.9 

I3-50 
23-03 
46.27 
45-37 
29.73 
9.17 

29-17 
16.03 
20.73 
20.80 
16.47 
30.63 
9.70 
31-30 
47.80 
47-20 
25-63 
17  03 

15.26 
24-33 
46.74 
46.58 

30.52 
9-44 
29.90 
16.25 
20.76 

I  .09 

2.14 
4-50 

4-49 

2.7! 
0-37 
2.65 
1.23 
1-79 

9.07 

IO.  12 
12.48 
12.47 
IO.69 

8-35 
10.63 
9.21 
9-77 

9-37 
10.43 
12.78 
12.77 
10.99 
8.65 
10.93 

9-51 
10.07 

1905  March  5.                                                    4O-INCH.                                                    Quite  good. 

'5     o 
15  30 

e 
b 
d 
1 

a 
2 

0 

e 

V 

V 

) 

V 

•y 
< 
3 
X 
a 
I 

d 
b 
c 
u 

26.5  27.7  25.8 
25-7  26.4  26.3 
16.3  17.2  16.  i 
52-8  54.3  53.0 
48.5  47.7  48.6 
34-8  34-2  34.0 
42.1  43.3  43.2 

36.7  36.3  37-2 
48.3  49.0  47.8 
44.0  44.0  44.6 
15.8  16.2  16.5 
15.0  16.2  16.3 
43-'  43-0  44.0 
46.2  44.8  45.7 
37.2  38.6  38.1 
44.1  45.2  46.1 
32-2  33-8  33-3 
45.1  46.0  45.8 
52.0  51.7  51.3 
15.5  16.9  16.8 
28.1  28.1   28.7 
26.5  26.7  26.6 
33  9  34-7  34-o 

26.67 
26.13 
16.53 
53-37 

48.27 

34-33 

42-87 

36.73 
48-37 
44-20 
16.  17 
15-83 
43-37 
45-57 
37-97 
45-13 
33-10 
45-63 
51-63 
16.40 
28.30 
26.60 
34.20 

26.64 
27.22 
16.46 
52  50 
46.95 
33-72 
44.00 
37-85 
46.47 

43-78 
16.00 

2-35 
2.38 
1.25 
5-03 
4-47 
3-05 
4.22 

3-53 
4.46 
4.18 
1.19 

12.05 
12.08 
10.95 

14-73 
14.17 

12-75 

'3  92 
13-23 
14.  16 
13-88 
10.89 

12-35 
12.38 
11.25 
15-03 
'4-47 
13-05 
14.22 

13.53 
14.46 
14.18 
ii.  19 

3  ii 

12.  8l 

13-11 

CHAPTER   V. — R  COM^E. 


TABLE  36. — 4315  R  COM.E.     PHOTOMETER  MEASURES  OF  COMPARISON  STARS. — Continued. 


1905  April  i.                                                   40-INCH                                   Fajr  to  good,  settings  good. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

h   m 
8  56 

Q    27 

0 

c 
b 
u 
d 

s 

a 

Z 
V 

y 

c 
0 

J3 
c 
V 
Tl 
2 
a 
1 
d 
U 

b 
c 

26.4  27.2  26.3 
23.8  24.1  24.7 
31.2  32.3  31.4 
14.1   12.4  13.2 
49.0  51.2  51.3 
42.3  43-8  43.3 
34-5  33-0  33  2 
38.8  41  .  i  40.0 
45.7  44.1  44.6 
36-3  36  4  36-9 
45-5  46-4  45-7 
10.0  12.6  11.7 
11.4  II  .1   13.1 
44.0  45.1  44.8 

35-o  35-9  35-7 
45.2  47.0  46.0 
39.2  37.8  38.8 
32.0  32.4  33.4 
40.8  38.1  38.9 

43-9  48-3  44-5 
14.2  15.0  14.2 
29.3  31.0  31.0 
18.8  23.0  22.1 

23-7  22.9  23.1 

26.63 
24.20 
31-63 
13-23 
5°  50 
43-13 
33-57 
39-97 
44.80 

36.53 

45-87 
"•43 
11.87 
44.63 

35-53 
46.07 
38.60 
32.60 
39-2? 
45-57 
14-47 
30-43 
21.30 

23-23 

24.98 
22.75 
31-03 
13-85 
48.04 
41.20 
33-o8 
39.28 

45-44 
36-03 
45-25 
11.65 

2.  2O 
2.OO 
2.76 
0.89 
4.62 

3-91 
2.98 
3-70 

4-37 
3-32 
4.36 
0.62 

12.26 
12.06 
12.82 

10.95 
14.68 

13-97 
13.04 
13-76 
14-43 
13-38 
14.42 
10.68 

12.56 
12.36 
13.12 
11.25 
14.98 
14.27 

13-34 
14.06 

14-73 
13-68 
14.72 
10.98 

1905  April  4.                                                                                                                                 Good. 

14  26 
15  02 

45 

c 

b 

u 

d 

i 

a 
Z 
V 

1 

c 
fi 
f 

(3 
e 
V 
11 
Z 
a 
i 

d 
u 
b 
c 

32.2  31.5  31.9 
31.9  32.1  31.9 

38-1  37  7  36.7 
16.2  17.3  16.8 

54-0  53-7  54-3 
47-5  48.9  48.3 
35-7  36-1  35-3 
40.7  40.4  40.9 
46.1  47.3  45.8 

37-3  38.6  38-7 
47.0  47.8  44.4 
16.0  15.2   15.9 
15.8  16.1    15.7 
45.1  44.8  46.9 
37-o  37-8  36.7 
44.6  47.5  46.3 
42-9  42.7  42-1 
35-0  34.9  35.0 
47-7  47-4  48-4 
55-2  57-o  55-o 
18.2  17.3  17.5 
34.0  35.0  36.2 
30.0  30.7  29.8 
3°-7  3i-7  3'   i 

31-87 
31.97 
37-50 
'6-73 
54.00 
48-23 
35-70 
40.67 
46.40 
38.20 
46.33 
15-70 
15-87 
45.60 

37.17 
46.07 
42-57 
34-97 
47-83 
55-73 
17.67 
35-07 
30.17 
3i.i7 

3I-52 
31-07 
36.28 
17.20 
54.86 
48.03 

35-34 
41  .62 
46.24 
37-68 
45-96 
I5-78 

2.81 
2.76 
3-34 
1-35 

5-21 

4.62 
3.22 
3-95 
4-45 
3-50 
4.42 
1.16 

12.28 
12.23 
12.81 
10.82 
14.68 
14.09 
12.69 
13-42 
13-92 
12.97 

13-89 
10.63 

12.58 
12.53 
13." 

II.  12 
I4.98 

H  39 
12.99 

13.72 

14.22 

13-27 
14-19 
10.93 

64  RESEARCHES   IN   STELLAR   PHOTOMETRY. 

TABLE  37. — 4315  R  COM*.    CONSTANTS  FOR  REDUCTION  AND  COMPARISON  WITH  CATALOGUE 

MAGNITUDES. 


6-INCH. 

1904  July  4.                                    ic 

(04  July  9.                               1905  January  12. 

Star.                   Obs.  Mag.        J  Mag.                    Ob: 

>.  Mag.        J  Mag.                   Obs.  Mag.         J  Mag. 

H.        P.        H.       P.                   H. 

P.        H.        P.                  H.       P.        H.        P. 

A....        0.83     7.98     8.28  +  .22  +  .  12     0.92      7.7 

B.  .  .  .  —  0.37    6.78    7.08  —  .13  +.04   0.05   6.9 
F....      0.42    7.57    7.  87-.  07-.  15    0.75    7.6 

9    8.  09+.  03-.  07    1.33    7.89    8.19  -f  .13  +  .03 
2    7.22  +  .01  +  .  18    0.18    6.74    7.04—  .17      .00 

2      7.92—  .02—  .10      I.  I  2      7.68      7.98   +  .04  —  .04 

Means..      0.29    7.44    7.74  ±  .14  ±  .10    0.57    7.4 
M0  7.15    7.45  6.8 

4    7-74±-°2±-i2    0.88    7.44    7.74±.n±.02 
7    7.17  6.56    6.86  

12-INCH. 

40-INCH. 

C. 

„                Mae. 

c 

St  L              Mae. 

'    Feb.  3.    Feb.  27.     Mar.  3. 

12-inch.     Mar   5         Apr   t         Apr   4 

a                       9.111  02          i  26          123 

R  9-35      i  o?          i   55          i  09 

77  .                             Q  .  S8         1.77               2    OO               I     7Q 

i  £7  10.10      2.16          2.  38          214 

Mean  C           ....       i   51           i  80          i   56 

Mean  Mag.       9.54      9.54          9.54          9.54 

M«   •                                           8.O^             7    74.             7    08 

Mean  Mag..    1  1  .  49        1  1  .  49          1  1  .  49          1  1  .  49 

MASK 
IS                 14                   13                   12 

ITUDE 
//                       10                       9                       tf                       7 

______  ._»_.._,.,___. 

so  :::::: 
:::::::::::::::::  4315  R  COMAE  

40  

-  +  -»H  
-__..__rEpI--.  -. 

-±  —  5E'  

::::::::::::::::.:i:::::::::  ::::::::::: 

1U  -''-  

1  _ 

30  

v>                —  -  
o.      
ui                           ; 

ft    i:::i::::i:i::::::::::;;:ii;;::iii;;ii! 
M:::::::i::::::::::;::i:i::::i:i::ii!i:i 
-  —  !  i  :  I  :  :  ;  i  I  :  

,  it  

_  r  3py.  -  -  - 

--^,ff-  ---  
:::!|:::::::::::::j::::|:::::::::::::::: 

10                                          jjjfflf  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 

::::::::!!:;::::::::::::::::::::::::::: 

•:&*:::    c  -  ::: 
•  ::J  ii::::±::::E:^EEE:::EE:E::EE:E:Ei; 

FIG.  13. — MAGNITUDE-CURVE  FOR  R  COM*. 


CHAPTER    V.  —  R  COM^E. 


TABLE  38.  —  4315  R  COHLB.     MEAN  MAGNITUDES. 


6-INCH. 

Star. 

July  4. 

July  9. 

January  12. 

Mean. 

Mag. 

A  Mag. 

Mag. 

J  Mag. 

Mag. 

J  Mag. 

Mag.  H. 

Mag.  P. 

4  Mag. 

A  

7.98 
6.78 

7-57 

+  0.09 
-0.03 
—  0.05 

7-79 
6.92 
7.62 

—  o.  10 

+  O.  II 

o.oo 

7.89 

6-74 
7.68 

o.oo 
—  0.07 
+  0.06 

7.89 
6.81 
7.62 

8.19 
7.11 
7-92 

±0.06 
±0.07 
±0.04 

B  .  . 

F  

Mean  ,  .  . 

7-44 

7-74 

±0.06 

a  ... 

9.  16 
9-56 
9-5i 
10.15 

+  0.05 

+  O.2I 
—  O.O7 
+  0.05 

8.98 
9.28 
9.66 
10.05 

-0.13 

—  0.07 
+0.08 
—  0.05 

9.18 
9.22 
9-58 

IO.  II 

+  0.07 

-0.13 

o.oo 

+  O.OI 

9.11 
9-35 
9-58 

IO.  IO 

9.41 

9-65 
9.88 
10.40 

±0.08 
±0.14 
±0.05 
±0.04 

R  

u  

\u 

Mean  

9-54 

9.84 

±0.08 

12-INCH. 

Star. 

February  3. 

February  27. 

March  3. 

Mean. 

Mag. 

J  Mag. 

Mag. 

A  Mag. 

Mag. 

J  Mag. 

Mag.  H. 

Mag.  P. 

A  Mag. 

9-05 
9.  10 
9.80 
10.  19 

—  0.04 
-0.05 
+  0.03 
+  0.05 

9.00 
9-29 
9-74 

IO.  12 

—  0.09 
+  o.  14 
-0.03 

—  O.O2 

9.21 
9.07 
9-77 

10.  12 

+  0.12 
-0.08 
O.OO 
—  O.O2 

9.09 
9-15 
9-77 
10.  14 

9-39 

9-45 
10.07 

10-44 

±0.08 
±0.09 
±0.02 
±0.03 

R  .  

u         

iU    

Mean  

9-54 

9.84 

±0.06 

12.  l6 

12.39 
10.65 

10.46 

-0.13 
—  0.04 

—  O.O2 

—  O.  II 

12.24 
12.42 
10.67 
10.63 

—  0.05 
—  O.OI 

o.oo 
4-0.06 

12-47 
12.48 
IO.69 
10.63 

4-0.18 
+  0.05 
+  O.O2 
+  O.O6 

6             

12  .  29 

12-43 
IO.67 

10-57 

12.59 

12-73 
10.97 
10.87 

±O.  12 

±0.03 
±0.01 

±0.08 

c         

d                     

/ 

ii  49 

ii   79 

±0.06 

40-INCH. 

Star. 

March  5. 

April  i. 

April  6. 

Mean. 

Mag. 

d  Mag. 

Mag. 

A  Mag. 

Mag. 

4  Mag. 

Mag.  H. 

Mag.  P. 

A  Mag. 

b   

12.08 
12.05 

10.95 
10.89 

—  0.04 
-0.15 
+  0.04 
+0.16 

12.06 
12.26 

10-95 
10.68 

—  0.06 
+  0.06 
+  0.04 
-0.05 

12.23 
12.28 
10.82 
10.63 

+  O.II 

4-0.08 
—  0.09 

—  O.  IO 

12.  12 
12.  2O 
lO.gi 
10-73 

12.42 
12.50 

II  .21 
11.03 

±0.07 

±O.  IO 

±0.06 

±O.  IO 

d     

/..                         

11.49 

11.79 

±0.08 

u      

12.81 

12.75 
14.17 
13  92 
14.  16 
14-73 
I3-23 

o.oo 
—  0.08 
+  0.09 
—  o.  16 

—  O.OI 

-0.03 

+  0.04 

12.82 
13-04 
13  97 
14.42 

14-43 
14.68 

I3-38 

-f-o.oi 

+  O.2I 
—  O.  II 

+0.34 
+0.26 

—  O.O2 

+0.19 

12.81 
12.69 
14.09 
13  89 
13-92 
14.68 
12.97 

o.oo 
—  o.  14 

+  O.OI 

—  o.  19 

-0.25 

—  O.O2 
—  O.22 

I2.8I 
12.83 
14.08 
(14.08 
(14.17 
14.70 
13    '9 

13.11 
I3.I3 
14-38 
H-38 
14-47 
15.00 

13-49 

o.oo 
±0.14 
±0.07 

±0.23) 
±0.17) 

±0.02 
±0.15 

z  

a 

ft     

i       

c 

66 


RESEARCHES    IN    STELLAR    PHOTOMETRY. 


TABLE  39. — 4315  R  COM.E.    VISUAL  OBSERVATIONS  OF  THE  VARIABLE. 


No. 

Date. 

u< 

• 

Aperture. 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing. 

t. 

J  Mag. 

Month 
and  Day. 

Hour 
C.  S.T. 

9 

8 

9 
9 
9 
9 
10 

10 

9 
9 
10 

IO 
IO 

9 

9 
9 
9 
9 

10 

9 
9 
9 
9 

8 
8 
8 
i? 
18 

18 
9 
9 
9 
9 

IO 

9 
8 
8 
8 
8 
8 
8 
8 
8 
17 
17 
i? 
17 

IO 
IO 

9 
9 

Julian 
"  Day 
G.  M.  T. 

Steps. 

Mag. 

i 

2 

3 
4 
5 
6 

7 
8 

9 
10 
ii 

12 
13 

14 
15 

16 

17 
18 

19 
20 

21 
22 
23 
24 
25 
26 

27 
28 

29 

3° 
3' 
32 
33 
34 
35 
36 
37 
38 
39 
40 

4i 

42 
43 
44 
45 
46 

47 
48 

49 
50 
51 
52 
53 

1894 
Mar.     9 
26 
Apr.      7 

22 

May     4 
10 
ii 

3i 
June     6 
18 

20 
24 

3° 
July     6 

23 

1896 
May   28 
June     6 
10 
30 
July     6 
ii 

24 
Aug.     3 

8 

10 

17 
26 
Nov.   1  2 

Dec.     2 

1897 
Jan.      7 
July     2 
8 
16 

21 

27 

Aug.     i 
6 
ii 
13 
19 
20 

24 
27 
29 
Sept.  27 

30 
Oct.     8 

25 

1898 
June  14 

July     5 
20 
Aug.     i 
9 

2410000+ 
2897 
2914.60 
2926.61 
2941  .64 
2953-63 
2959-63 
2960.63 
2980.67 
2986.65 
2998.63 
3000.63 
3004.67 
3010.67 
3016.65 
3033-63 

3708.63 
3717-63 
3721-63 
374I.63 
3747.67 
3752.63 
3765-63 
3775.63 
3780.63 
3782.58 
3789-58 
3798.57 
3876.96 

3897.00  | 

3933-00 
4108.63 
4114.63 
4122.63 
4127.63 
4133-67 
4138.61 
4*43-58 
4148.58 
4150.58 
4156.58 
4J57-58 
4i6i.57 
4164-57 
4166.57 

4195-96 
4198.96 
4206  .  96 
4223-96 

4455.67 
4476.67 
4491-63 
4503.61 
4513.6 

150? 
150? 
150? 

150 

150 
40 
150 

150 

150 

40 

150 
40 

150 

150 
150 
150 

40 

80 
40 

40 

ISO 

40 

150 
40 
40 
40 
40 
40 
40 
40 
40 
40 
40 
40 
40 
40 
40 

150 
40 
40 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

12 
12 
12 
12 
12 

<I2 
<I2 
<I2 
<I2 
<I2.3 

poor 
good 
good 
fine 
fair 
poor 
good 
good 
good 
fair 
fair 
fair 
good 
moon 
fair 

good 
fair 
fine 
fair 
good 
poor 
moon 
fair 

fair 
fair 
fair 
good 

good 

good 
good 
good 
good 
good 
good 
good 
good 
good 
poor 
fair 
good 
fair 
fair 
good 
poor 
poor 
good 
good 

fair 
fair 

poor 
fair 

o 

H 
18 

24 
3° 
47 

2 
I  I 

15 

35 
4' 
46 
59 
69 
74 
76 

83 
92 
170 

191 

227 
42 
48 
56 
61 
67 
72 
77 
82 
84 
90 
9i 
95 
98 

IOO 

132 
140 
157 

29 
50 
65 

77 
87 

-0.74 

—  o.  70 
—  0.60 

-0.43 

—  O.2I 
-0.72 

-0.73 

+  0.80 
-  +  0.48 
-0.73 

+  o.  15 

+  0.35 
+  0.25 
+  0.20 
+  O.22 

+  0.24 

+  O.O2 

+  0.28 
+  O.2O 

-0-34 
—  O.6o 
—  0.42 
-0.36 
-0.58 

-0.34 
—  O.6O 
-0.51 
—  0.50 
—  0.42 
-0.49 
—  0.50 
-0.51 

+  0.03 
+  0.30 
+  0.58 

+  0.57 
+  0.60 
-0.03 
—  I  .O2± 
-0-45 

TJ  not  seen  limit  <  i2M    .   .  . 

<I2.4 
<I2.3 

12.26 
<n.8 
11.85 
11.80 
ii  .61 
ii  .61 
10.27 

<I2.O 

11.88 

15.6 

<i9 
18.6 
19.0 

2O.  2 
2O.  2 
30-4 

<I7 

8.3 

DC    "VI—  2b        

18.6,   18.6  

n-2c,  Tii-2b,  eyv  

V2C,  ei-2V  
T12-y,  €2T1  

xi-2v,  t)4/,  f$e  
~v  not  seen   limit  4<  e    .  .  .  . 

20.  i,   18.6,   18.3  .  . 
20.  6,   19.8  
21.  i,   19.3  
30.4,  30.4  

v  glimpsed   031??    

V  not  seen   limit  3<Ce 

<i8 
17-3 
21.3 
37-5 
36.0 

36-3 
37-8 
39-8 
40.4 
26.4 

21.6 

13.8 

21.8 

28.1 

35-2 
37-8 
39-4 
43-8 
46.2 
46-3 
45-9 
46.4 
45-8 
46.4 
46.6 
46.8 
<53 
39-3 
35-8 
27.9 

13-7 

22.6 
36.2 
48.6 
46.0 

<n  .9 

12.  OI 

11.48 
9.38 
9.58 
9.53 
9.35 

9.  10 

9.03 
10.79 

II  .42 

12.50 
II  40 

10.58 
9.68 
9.36 
9.12 

8.61 
8-33 
8.32 
8.37 
8.31 
8.38 
8.31 
8.30 
8.28 
<7-5 
9.15 
9.60 
10.60 

12.52 
11.30 

9-55 
8.06 

8-35 

e$v  limit  i<v     

•ve±  .            

Rl    2V                                         .     .  . 

RlV,  TII-2    lU  

Rv±,vi   lU  
vo-jR,  T12-T,  iV,  ayv,  pyv. 
•vo-iR,  P-^-afU,  a\—2Ti  
vR,  P3~  41),  via  
•vf,  iiid,  -vSe  

d^V,  T1I-2C  

ofay                        

37-0,  34-1  
39  o,  33.6  
39-0,  35-1,  37-9,  39-2 
39-5,  40.7,  39-4  •  • 
39.0,  40.7,  41.4  .  . 
26.4,  26.4,  29.3  .  . 
21.4,  22.8  ) 

IO   4. 

«6-8i),  e*yv  
Tie,  dyi  

T12d,  ZT}/,     lt/5Z)  

RSV,  1)3-4  it/,/?3-4"  

'4-3,  13  3  
21.3,  22.4  
27-4.  29.4,  27.6  .  . 
34.0,  36.1,  35.5  .  . 

^7     c      18    I 

•viR,  a2V  
•vdR,  Po-iv,  Ti2-yi  

•V2P        

40.0,    38.9  

45-0,  43-7,  43-4  •• 

F6v,  T12P,   HT,-$V  
Fyj,  tiiP,  #3-41)  
Ft,v,  -viP,  Hyv  
F^v    iiiP,  H$v  

46.9,  46.2,  45.7  .  . 
47-9,  45-2,  45-7  •• 
47-9,  45-2,  46-2   .. 
47.9,  45.2,  45.2   .  . 
47-4,  46  •  7.  45-2 
47.9,  46.2,  45.7  .  . 
47.9,  46.2,  46.2   .  . 

Fs-6i>,  -V2-T,P,  H$v  
F$v,  -V2P,  H  3-4.11  
FSTI,  V2P,  Hyi  

P4-5-V,  TiR±     
Ryv,  1)3  lU  

39-7,  39  o  
36.o,  35.6  
28.6,  27.4,  27.4  .. 

H-i.   13.3  

22.8,     22.4  

37-6,  34-9  
44-9,  52.2  
42.9,  49.2  

C4-5D,   1>2Z  

vi—  2e,  d?,v  
1)5   ill,  a6v  
F&v,  i)8P  

FlOTl,    V5P  

CHAPTER  V. — R 


TABLE  39. — 4315  R  COMJB.    VISUAL  OBSBRVATIONS  OP  THE  VARIABLE. — Continued. 


No. 

Date. 

Ocular. 

i 
t, 

B, 

< 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing. 

t. 

J  Mag. 

Month 
and  Day. 

Hour 

C.S.T. 

Julian 
Day 
G.  M.  T. 

Steps. 

Mag. 

54 
55 
56 
57 
58 

59 

60 
61 
62 
63 
64 

65 
66 

67 
68 

69 
70 

7i 
72 
73 
+  73 
74 
75 
76 
77 
78 
79 
80 
81 
82 

83 

84 
85 

86 

8? 
88 
89 
90 

9i 
92 

93 

94 
95 
96 

97 
98 

1898 
Aug.    19 

27 
Sept.    2 
Nov.  14 
Dec.   23 

1899 
Dec.    14 

1900 
Jan.    20 
Feb.      i 

9 
18 

24 
Mar.     2 

21 

22 

Apr.     4 

6 

18 
18 

27 
May     8 

9 
24 
25 
28 
29 
30 
June     8 
15 
23 
26 

July   10 

21 

25 
28 

Aug.     6 

13 
'3 
H 
18 
Oct.    25 

1901 
May   1  8 

1902 
Jan.    10 
Feb.    ii 

22 

Mar.   15 
Apr.  12 

9 

8 
8 

17 
18 

18 

13 
18 
16 
13 
II 

1  1 
ii 
ii 

13 

H 
9 

10 

8 
ii 

9 
10 

9 
9 
9 
9 

8 

9 

8 

9 

8 

8 
17 

13 

14 

12 

13 
12 

2410000+ 
4521  .60 
4529-58 
4535-57 
4608  .  96 
4648  .  oo 

5004.00 

5040.79 
5°53  oo 
5060.92 
5069.79 

5073-71 

5081 
5100.71 

5101  .68 

5"4-79 

5116.81 
5128.63 
5128.65 
5I37-7 
5148-7 
5H9-7 
5i64-7 
5165.7 
5168.7 
5169-7 
5170.58 
5I79-69 
5186.63 

5I94-67 
5196.63 

5211-63  -< 
5222.61 
5226.63  -j 

5229-58  \ 
5238.60  -J 

5245-58 
5245-58 
5246-58 

5250-  58  { 

5318.54 

5523-77 

5760.83 

5792.75 
5803 

5824.79 
5852-75 

80 
80 
40 
150 
150 

350 
150 
i?5 
350 

350 

275 
275 
350 

275 

350 
350 
275 
237 
350 
237 
275 
80 

275 
237 
237 
237 
150 
40 
150 
150 
40 
40 

80 

40 
40 
150 
40 
40 
40 
40 
150 
40 
67 

80 

237 
237 

350 
23? 

12 

6 
6 
6 
6 

6 

40 
6 

12 
40 

40 

12 
12 
40 
12 

40 
40 
12 
40 
40 
40 
12 
12 
12 
40 
40 
40 

6 
6 
6 
6 
6 
6 

12 

3 
6 
6 
6 
6 
6 
6 
6 
6 
6 

12 

12 

40 
40 

24 
40 
40 

PlTl,    ilIO-12     lU,    V6-^R  .  . 

FIZTJ,  P$-$v  

42.2,  43.6,  46.5 
40.9,  38.7  

43-3 
39  4 

40.3 

22.6 
14.9 

18.3 
14-3 

<i5 
8.8 

5-9 
6.6 

<8 

<6.3 
4.0 

3-5 

7.0 
8.8 
<9.o 
8.8 
9-4 

8.67 

9-13 
9.04 
11.30 
12.38 

11.88 
12.42 

<I2-3 

13,12 
13-68 

13-56 

<i3-3 
<I3-6 
13-95 
14.05 

13-50 
13.22 

''IS- 
IS   2 

I3-I7 
13-24 
12.65 
12.56 
12.52 
12.44 
12.51 
11.58 
ii  .40 
11.19 

II  .  IO 

9.87 
9-52 
9.24 

9  52 
9-45 

9.24 
9-05 
9.02 

9-38 
n.  18 

12.85 

12.80 
13-42 

fair 
good 
fair 
good 
fine 

fair 
good 

fair 
fair 

fair 
fair 
good 

good 

fair 
fair 
poor 
good 
fair 
poor 
good 
good 
good 
good 
good 
low 
fair 
good 
fair 

fair 
fair 
good 

good 
fair 

95 
103 
109 
182 

222 

218 

254 

274 
283 

287 

315 
328 

330 
342 

2 

3 
18 

19 

22 
23 

24 

33 
40 
48 
50 

65 
76 
80 

83 
92 

-0.23 

+  0-33 
+  0.24 

+  O.22 
+  0.24 

-O.I? 

—  O.2I 

—  O   OI 

+  0.36 

-0.18 

+  0.25 

+  0-35 
-0.30 
—  0.28 

+  0.17 
+  0.26 
+  0.36 
+  0.31 
+  0.41 

+  0.34 
+  0.41 

—  O.  IO 

o.oo 

+  O.2I 
+  0.40 

+  0.32 
+  0.44 
+  0.25 

+  0.62 
+  0.65 

in—  22,  c^v,  631),  cyv    

12.8,  17.3,  14.1,  15.6 
18.3,  18.3  

eyv,  vie2  

•JJ7Z 

v  not  seen,  limit  2  <  6  .... 

22—311  ?  not  sure  

251>,    TJ2—  3<x  

6l        <\      5    .   . 

lzW>>    T2-3a    
^0Ia     036,    "yla  

7-8,  5-5  | 

v  not  seen,  limit  3<Cz  

v  not  seen,  limit  4—  5<z..  .  . 

I  a,  ft,  •/  «  and  ,  seen,  limit  y 
(  v  quite  certainly  glimpsed 
tyv,  1147,  zi-2f,  ^4-57  
T'3r,  vi-2,,  zSv±  
11  not  held,  .  seen  

6.0,  8.0  
7-0,   10.5  

Z2V,   Vt,    t'4y  
22-31),    VI,  

photometer   

9.3,  9.0,  8.0  
8.8,   10.  o  

e*%-iav,  T>i-2z,  limit    2<z 

1)22    ...     .                  

12.8 

13-3 
13-7 
14-3 
13-8 

641),  vys  
ea8i>,  7132  
•V2Z,  e*8v,  T>T,Z  
photometer  

I3-I,   14-3  
(8.3),   14-3  
13-3.   14-3  

21.8 

23-4 
24.0 

33  6 
36.3 
37-8 

36.6 
36.0 

dn)    V2e    fyv    1)6—  86      .  .  . 

23.4,23.4,23.4(24.1) 
23-4,      28-3    
•32    A.                                  .  .  ) 

d2v,  v(t-8e  
•v6~8d  

113  i  U,  R&v  
Ryv,  t>4  1  1/  
Riv,  115  lU  

RlTl,    T}$lU  

R2V,  113  it/  
photometer  

35-6,  31.0  ) 
36.0,  36.6  
38.0,  37.6  \ 
38.0,  37.6  1 
37-o,  35-6  \ 

112—  3    lU  

T.6     I  .  .                                   .    \ 

Rw 

36  o                         / 

photometer  

V2R,  t>6-8  it/  

•VI-2R               

4'  o,  39.6  

40.3 

40-5 

37-6 
23-4 

H.  3 

good 
good 

good 
fair 

fair 

poor 
fair 

99 

IOO 

104 

172 

17 

254 
286 

+  0.30 
+  0.22 

+  0.58 
+  0.48 

+  0.45 

—  O.O2 
+  O.  IO 

v^—  5  iU    

17  i    .                   .1 

Kiv                      

18  o                         ( 

dm,  vii  
t>z    near  limit    

24-4,  22.3  

photometer  

photometer  

photograph  

5.8,  9.0  7.0,  7.0. 

6.6 

13-57 
13-48 

fair 
good 

3i8 
346 

-0.13 
+  O.06 

photometer  

68 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABLE  39- — 4315  R  COM/E.     VISUAL  OBSERVATIONS  OF  THE  VARIABLE.— Continued. 


No. 

Date. 

Ocular. 

Aperture. 

Comparison. 

Reduction,  Steps. 

Means. 

Seeing. 

t. 

J  Mag. 

Month 
and  Day. 

Hour 
C.  S.  T. 

Julian 
Day 
G.  M.  T. 

Steps. 

Mag. 

99 

100 
IOI 
IO2 
103 
104 

105 
106 

107 
1  08 
109 

I  1O 

in 

112 

"3 
114 

»5 
116 

H7 

118 
119 

1  20 

121 
122 
'23 
124 

125 
126 
127 
128 

129 

130 
131 

1901 
May     2 

25 
June     3 

9 
25 
30 

1903 
Jan.      9 
May    17 

1904 
Mar.   22 
May     3 

10 

June  17 

J«iy    4 

9 

Aug.     2 

27 
1905 

Jan.      3 
29 

Feb.   27 
Mar.     5 

12 

24 

25 
26 
Apr.      i 

4 

8 
1  1 
30 
May   31 

June  22 

July   24 
Aug.     9 

13 

M 

10 

9 

10 

9 

16 
9 

13 
10 

7 
ii 

10 

9 

8 

«  3 

14 

10 

15 
13 

9 
10 

10 

9 
'4 

9 
15 

10 

9 
9 

9 

8 

2410000+ 
5872.77 
5895.83 
5904.67 
5910.63 
5926.67 
593'  63 

6124.92 
6252.63 

6562.79 
6604  .  67 
66  1  1  .54 
6649.71 
6666.67 
6671.63 
6695  .  6 
6720.58 

6849.79 
6875.83 
6904  .  67  -j 

6910.88  | 
6917.77 

6929.60 

6930.67 
6931.67 
6937-63 
6940.83! 

6944.63 
6947  96 
6966  .  67 
6997  63 

7019.63  -^ 

7051-63 
7067.60 

237 
237 
67 
67 
67 

67 

237 
67 

237 
67 
40 
40 
40 
40 
67 
40 

237 
237 
67 
275 
237 
237 
237 

150 

250 
237 
237 
237 
237 
237 
237 
237 
150 
40 
150 
40 
40 

40 
40 

12 
12 
12 

12 

40 
12 

40 
12 

6 
6 
6 
6 

12 

6 

40 
40 

12 
12 
40 
40 
40 

6 

40 
40 
40 
40 
40 
40 
40 
40 
6 
6 
6 
6 
6 

photometer  

12.71 

12.  14 
11.49 
11.03 

9-43 
8.97 

13.28 
<n.7 

13-50 
12.9 
12.67 
10.54 
9-54 
9.29 
8.41 
8.78 

12.  29 
13.00 
<I2.9] 

13.31} 
13.90 

13.59 

<I2.9 

13.45 
(14.42) 
13  76 

13.43 
13.20 

13.48 

12.92 
11.50 

9.90 

8.90 
9.18 

good 
fair 
fine 
fair 
fair 
good 

fair 
poor 

fine 
dull 
good 
fair 
fair 
good 
good 
good 

good 
good 

good 

good 
good 

fair 

good 
fair 
fair 

good 

fair 
low 
good 
fair 

poor 

good 
fair 

6 
29 
38 
44 
60 

65 

258 

336 
18 
25 
63 
80 

«5 
109 

'34 

263 
289 

3i8 

324 
33i 

344 
3S4 
3St 

358 
i 

12 
2O 
51 

73 
105 

121 

-0.17 

+  O.22 
—  0.03 
—  0.08 
-0.36 
—  O.DO 

4-0.38 

—  0.  II 
+  0.5 

+  0.58 

+  0.88 
+  0.55 
+  0.39 
-0.39 
—  0.40 

—  0.70 
-0.39 

-0-39 

+  O.2I 
—  0.  10 

-0.03 

+  o.  17 
+0.46 

+0.05 

+  0.60 
0.50 
+  0.72 
+  0.90 

+0.70 

+  O.  12 
+  0.27 

photometer  

photometer  

photometer  

photometer  

photometer  

241",  Vt(T>,  v8y  
TJ  not  seen,  limit  iM<rf.  .  .  . 

7.3,  9.0,   12.0  

8.6 

photometer     

14.1,   16.5,   13.3  .  . 
12.5,   12.8  

14.6 

12.7 

uyv,  V1-2Z,  z  glimpsed.  .  .  . 
photometer  

photometer     

photometer  

photometer  

Pi—  2V,  a  or  R  not  seen  .  .  . 

42.7 
15.3 

IO.2 

<n.3 

8.3 

4.3 

6.5 
<n 

7-4 

1)±Z  .  . 

Z1V,    Tie  

i)  not  seen,  limit  2  

10.3,   10.  o  

i)  glimpsed  ?  231?^  

4.5,  4.5,  4.0  ...  I 

photometer  

«3"y,    v^y  

6  -O.    7  .O  .  . 

(ttand  companion  both  seen, 
-'  z    limit,   about    I2M.6,    v 
(not  seen. 
251),   ell),  1>4y  
photometer  

) 

> 

6.3,  8.0,  8.0  

photometer  

ei7>,  vyf  

8  .  o,  7  o  . 

71 

photometer  

<o—w   7)6v  

8.5    10  o 

9.0 

7-2 

10.8 

21  ,O 

33-3 
41.7 
39-3 

e2D     7)3—4?  

7  -O,  7  5 

v  5-67,  7>2<i,  vz  
d$v,  Tie,  716=86  

R2V,    11-lU  

v^d   

9.5,  u.  o,   11.3  
21.4,  21.3,  24.1   .. 
37-o,  32.6  ) 
30  .  4  ...                    ) 

Pyj,  va,  v6R  
P67),  am    

41.2,  40.9,  45.0  .  . 
38.2,  39.9  

CHAPTER  V. — R 


01 

<0 


«0  Q 


<00 

^     °> 


O     § 

o 

Q^       « 
if)  W 


69 


y  5  * 

FlG.    14. — LIGHT-CURVB  OF  R 


RESEARCHES    IN    STELLAR   PHOTOMETRY. 

TABLE  40. — 4315  R  COM^B.    MEAN  MAGNITUDES  FROM  30  DAY  GROUPS. 


Group  No  .... 
]    D    

i 

30 

2 
60 

3 
90 

4 
1  20 

5 
15° 

6 

1  80 

7 

210 

8 
240 

9 

270 

10 
300 

II 

330 

12 
360 

f 

2986   \ 

1 

1 
3706   ^ 

1 
4066  . 

4426   . 
4786   . 
5146 
5506 
5866 
6586 
6946 
Mean 

t 
M 

JM 
No. 

t 
M 
JM 
No 

t 
M 
4M 

No. 

t 
M 
JM 
No. 

r  i 

JM 

No. 

[      M 

I     JM 
[_  No. 

r  >: 

JM 
L  No. 

r  ^ 

1     JM 
L    No. 

(  «' 

1     JM 
L   No. 

(  J 

1     JM 
L   No. 

.1  » 

51    JM 
L  No. 

H 
11.87 
0.62 

4 

ii 
11.88 

-0.73 
i 

29 
12.52 

+  0.57 
i 

38 
10.94 
—  0.46 
2 

48 
10.96 
4-0.18 

3 

49 
10.55 
-0.25 

3 

50 
11.30 
+  0.60 

i 

76 

9-39 
-0.24 

4 

74 
8.68 
-0.47 
6 

76 
8.65 
—  0.50 
3 

92 
9  03 

-O.22 

I 

95 
8.32 
-0.48 

5 

IO2 

8.95 
+  O.II 

3 

136 
9-38 
-o.  16 

2 

170 
10.79 
-o.  24 
I 

157 

10.60 

+  0.58 

i 

I9O 
II  .42 
-O.O2 
I 

227 
12.50 
+  0.28 

i 

182 
11.30 
+  0.22 

I 

222 

12.38 
+  0.24 
I 

218 
11.88 
-0.17 
i 

254 
12.42 
—  O.2I 

I 

281 

13-45 
+  0.18 

3 

322 

14.00 
+0.30 

2 

336 
J3-36 
—  O.29 
2 

15 

12.58 

+  0.22 

7 

17 
12.85 
+  0.45 
i 

18 
12.42 

+  O.O2 

22 
12.  8± 

+  0.5± 

43 
11.32 
+  0.13 
4 

76 

9-54 
+  0.41 

4 

99 
9.24 

+  0.44 
4 

172 
11.  iS 
+  0.48 

2 

254 
12.80 
—  O.O2 
I 

258 
13.28 
+  0.38 

I 

263 
12.29 
—  O.7O 
I 

286 
13-42 
+  O.  IO 
I 

289 
13.00 
-0.39 

I 

318 

13  57 
-0.13 
i 

321 
13.61 
—  0.09 

2 

346 
I3-48 
+  0.06 
I 

336 
I3-50 
—  O.  H 
I 

343 
13  56 
+  0.14 
4 

4i 
11.26 
—  0.06 

2 

62 
9.20 
-0.48 

2 

76 
9.46 
+  0.6I 

109 
8.41 
-0.39 

i 

134 
8.78 

—0.40 
I 

17 
12.40 

±O.O2 

18 

45 
11.03 

—  O.OI 

15 

74 
9.12 
—  0.03 

22 

98 
8.78 
—  0.03 
i. 

135 

9.18 

—  0.03 

168 
10.94 
+  0.4; 

4 

1  86 
11.36 

+  0.12 

222 
12.25 
+  O.  12 

257 
12.70 

—  o.  14 
4 

284 
13.35 

+  0.05 

1 

321 
'3    76 
+  O.O6 

c 

341 
13-49 

—  O.OI 

8 

CHAPTER   V. — R 


TABLE  41. — 4315  R  COJLE.    OBSERVED  MAXIMA  AND  MINIMA. 

Elements  of  maximum.     1856  Dec.  20  (J.  D.  2399304)+361.8d  E.     M-m=119d. 


MAXIMA. 

MINIMA. 

I 
W 

Date. 

Mag. 

Corr. 

Wt. 

4 
13 
23 
15 
17 
i 

4 

5 
5 

i 

6, 
W 

Date. 

Mag. 

Corr. 

Wt. 

Calendar. 

J.  D. 

H. 

P. 

Calendar. 

J.  D. 

H. 

P. 

38 
40 

4i 
42 
44 
45 
46 
48 
49 

1894  Sept.  3 
1896  Aug.  30 
1897  Aug.  19 
1898  Aug.  23 
1900  Aug.  10 
1901  Aug.  15 
1902  July  29 
1904  July  28 
1905  July  24 

3075 
3802 
4156 
4525 
5242 
5612 
5960 
6690 
7051 

me 

8.92 
8.40 
9.o± 
9.20 
me 
me 
8.40 
8.90 

9.22 

8.70 

9-3± 
9-50 

8.70 
9.20 

+  23 
+  26 
+  18 
+  25 
+  19 
+  27 

+  13 

+  20 
+  19 

40 
41 
42 
43 
44 
45 
46 

47 
48 

49 

1896  Apr.  30 
1897  Apr.  14 
1  898  Apr.  13 
1  899  Apr.  i 
1  900  Apr.  i 
1901  Mar.  26 
1  902  Mar.  17 
1  903  Feb.  25 
1  904  Mar.  24 
1  905  Mar.  17 

3680 
4029 

4393 
4746 

5"i 

5470 
5826 
6171 
6564 
6922 

me 
me 
me 
me 
13-98 
me 
'3-73 
i3-7± 
me 

13-67 

+  23 
+  9 

+  12 

+  4 
+  7 
+  4 

—  2 
-19 
+  13 

+  9 

2 

4 
4 

2 

27 

3 
ii 

i 

3 
18 

14.28 

14-03 

14.  o± 

'3-97 

TABLE  42.- — R  COM^E.    VARIOUS  DETERMINATIONS  OF 
COMPARISON  STARS. 


J.'A. 

Star. 

Hagen. 

HCO. 

H.  M. 
Parkhurst. 

Parkhurst. 

H. 

p. 

F 

8.2 

7.61 

7.82 

7.62 

7.92 

a 

8.6 

8.90 

9.09 

9  39 

R 

8.8 

9.01 

9  36 

9.15 

9-45 

lU 

93 

9.62 

IO.  II 

10.  14 

10.44 

d 

IO.O 

10.81 

10.97 

10.67 

10.97 

c 

10  8 

12    46 

u 

13.20 

12.  8l 

13.11 

Some  of  the  various  magnitude  scales  for  the  comparison  stars  are  collected 
in  Table  42.  It  will  be  seen  that  the  Hagen  scale  is  very  much  compressed, 
the  interval  between  F  and  c  being  only  2.6  magnitudes,  whereas  it  is  4.81  by  my 
measures  and  4.85  by  the  Harvard  measures.  This  may  be  due  in  part  to  the 
yellow  color  of  the  star  F,  but  seems  mainly  due  to  the  star  c.  No  magnitudes 
have  heretofore  been  published  for  stars  suitable  for  comparison  with  the  variable 
near  minimum,  evidently  because  it  has  not  been  observed  at  that  part  of  the 
light  curve. 

The  redness  of  the  variable  is  given  as  4.0  in  Chandler's  Third  Catalogue. 
Photographically  it  is  at  least  one  magnitude  fainter  than  r  at  minimum. 


RESEARCHES   IN   STELLAR  PHOTOMETRY. 


PAYS 

100  zoo  '  300  400 


+315  R  COMAE 


Max.   - 
Mm.    •  3Z2 
M-m  «   /*<? 


10 


o 

\» 

o 

I 


FIG.  15.— MBAN  LIGHT-CURVB  OF  R  COMM. 


CHAPTER  VI. 


5798  RU  HERCULIS. 
R.  A.  i6h  6m  2s  7;  Dec.  +25°  19'  56"  (1900). 

This  is  another  of  Anderson's  discoveries,  to  which  Chandler  assigned  the 
above  notation  in  the  Astronomical  Journal  17,  64.  Some  confusion  may  arise 
from  the  number  57963  being  given  it  in  the  Astronomische  Nachrichten.  The 
announcement  of  discovery  was  made  in  1896  and  observations  began  in  January, 
1897.  One  other  series  has  been  published  by  H.  M.  Parkhurst  and  A.  C.  Perry. 
The  details  of  Hartwig's  observations  have  not  appeared,  while  Esch  has  pub- 
lished only  three  comparisons. 

The  places  of  the  brighter  comparison  stars  were  measured  in  July,  1897, 
with  the  6-inch,  and  the  fainter  stars  o,  m,  n  and  g  in  June,  1900,  with  the  40- 
inch.  These  places  have  all  been  checked  on  the  photograph.  The  star  p  was 
selected  and  used  with  the  6-inch,  but  its  photometric  magnitude  was  measured 
only  with  the  4O-inch,  and  seems  to  be  too  large  numerically. 

The  place  of  the  variable  given  above  was  found  by  applying  the  coordinates 
in  Table  45  to  the  Cambridge  A.  G.  positions  of  the  stars  a,  b,  s,  and  /.  It  agrees 
closely  with  that  given  by  Hartwig. 

The  light  curve  shows  considerable  range  in  the  magnitude  at  maximum, 
at  least  from  7.4  to  8.8  on  the  Harvard  system,  with  the  alternate  maxima  bright. 
The  minima  are  more  uniform  at  about  14.0.  There  is  an  unmistakable  halt 
in  both  branches  of  the  curve,  at  somewhat  different  magnitudes.  This  does 
not  amount  to  a  secondary  maximum,  if  we  may  trust  the  evidence  before  us. 

The  last  comparison  used  in  forming  the  mean  light  curve  is  that  of  1905, 
January  12. 

5798  RU  HERCULIS. 
TABLB  43. — STANDARD  MAGNITUDE  STARS. 


Star. 

B.  D.  No. 

1900. 

Color 
P.  DM. 

Magnitude. 

Residuals. 

R.  A. 

Dec. 

Catalogue. 

Measured. 

From  Cats. 

3 
Nights 
inter 
se. 

H.C.O. 

RDM. 

H. 

P. 

H. 

P. 

B 
C 
I 

O 

+  27  2595 
+  27  2597 
+  25  3039 

Mean  .  . 

h    m    s 
16  05  58 
16  07  01 
16  05  56 

0               / 

+  27  00.5 
+  27  09.8 
-t-25  44-8 

GW  + 
GW- 
GW- 

6.68 

7-37 
7.48 

6.88 
7.80 
7.68 

6.62 

7-53 
7-39 

6.89 
7.80 
7.66 

-  6 
+  16 
-   9 

+    i 
o 

—     2 

±   7 

±    2 

±   4 

7.18 

7-45 

7.18 

7-45 

±10 

±     I 

±   4 

73 


74 


RESEARCHES  IN   STELLAR   PHOTOMETRY. 


TABLE  44. — 5798  RU  HERCULIS.    COMPARISON  STARS  IN  B.  D.  CATALOGUE. 


B.  D. 

1855- 

B.  D. 

1855- 

No. 

Mag. 

R.  A. 

Dec. 

star. 

No. 

Mag. 

R.  A. 

Dec. 

O 

h  m  s 

•    t 

O 

h  m  s 

O       ' 

11 

+  25  3031 

8.3 

16   I  21 

+  25  17.9 

X 

+  25  3040 

9-5 

16  4  28 

+  25  50-0 

t 

+  25  3036 

8.4 

16  2  48 

+  25  18.8 

a 

+  25  3042 

8.5 

16  5  19 

+  25  20.2 

2 

+  25  3037 

9-5 

16  3  29 

+  25  53-5 

s 

+  25  3044 

8.8 

16  5  23 

+  25  48.2 

•w 

+  25  3038 

95 

16  4  2 

+  25  6.5 

b 

+  25  3046 

9.0 

16  5  48 

+  25  36.5 

TABLE  45. — COMPARISON  STARS  FOR  RU  HERCULIS. 


Star. 

Coordinates  from  Variable. 

Light 
Scale, 
Steps. 

Magnitude. 

R.  A. 

Dec. 

Measured. 

From  Curve. 

H. 

P. 

H. 

P. 

n 

s 

ft 

u 

-2273 

-167.9 

-   558 

26.5 

8.81 

9.08 

t 

—  I  IIO 

—   82.0 

-   493 

26.7 

8.80 

9.07 

z 

—    560 

-   4i-4 

+  1580 

17.0 

10.15 

10.42 

•w' 

-    208 

-    15-4 

+        i 

-7-5 

14.68 

14-95 

y 

-     199 

-    J4-7 

+  2575 

17-5 

10.36 

10.63 

P 

-     179 

-   13-2 

-   315 

o 

13-42 

13.69 

t' 

-     99 

-     7-3 

—       12 

-9.1 

15-23 

15-50 

•y 

—        QJ. 

—     6  q 

CJ.fi 

i 

V*r 

-    87 

**  '  " 

-     6.4 

ot^ 
+  1491 

34-0 

7-39 

7.66 

•w 

-    84 

-        6.2 

-1239 

15-0 

10.77 

n  .04 

i 

-     59 

-     4-4 

+     368 

IO.O 

ii  .64 

ii  .91 

q 

+     24 

+     1.8 

-     481 

12.0 

n  .29 

11.56 

n 

+     35 

+       2.6 

—     184 

2.8 

12.75 

13.02 

m 

+     44 

4-     3-3 

~     243 

4-i 

12.40 

12.67 

g 

+     9i 

+     6.7 

-     49 

8.0 

11.96 

12.23 

h 

+    187 

+   13-8 

+    191 

6.0 

12.06 

12.33 

X 

+   232 

+   17-1 

+  1342 

16.4 

10.54 

10.81 

c 

+   267 

+    19-7 

+  669 

14.0 

10.94 

II.  21 

e 

+   313 

+   23.1 

+  423 

IO.  I 

11-39 

ii!66 

d 

+   473 

+   35-o 

+   77i 

13-' 

11.09 

11.36 

a 

+   921 

+  68.1 

-   384 

29.7 

8.61 

8.88 

s 

+   981 

+   72-5 

+  1239 

26.9 

9.22 

9-49 

b 

+  1335 

+   98.6 

+   580 

21.0 

9  58 

9.85 

STELLAR    PHOTOMETRY. 
+  im 


N 
om 


PLATE   6. 


•x 


•  s 


.a 


•  c 


.f 


i 


0 


•n 


-w 


u 


1-  20' 


-+  10' 


--  10' 


Scale,  i  mm=  15".  3. 


5798  RU  HERCUUS. 

R.  A.  i6li  6m  2s.7.     Dec.  +  25°  19'  56",  1900. 


CHAPTER    VI. — RU    HERCULIS. 
TABLE  46.— 5798  RU  HERCULIS.    PHOTOMETER  MEASURES  OF  COMPARISON  STARS. 


75 


1904  July  31                                                     6-INCH.                                Good;  twilight  at  beginning. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

klean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

h     m 
I?  °5 

17  25 

o 
20 

24 
24 

23 

C 
B^ 
I 

z 
s 
b 
a 
•v 
a 
b 
s 
z 

/ 

B.,, 
Cat 
C 

n  .  i    11.7   10.3 
7.0     8.1     8.7 
9.2     9.0     9.  i 
34.1  34.0  32.9 
25.3  25.0  25.3 
27.8  28.2  27.6 
18.7  J8.9  18.6 
42.8  41.5  42.7 
18.8  18.9  19.8 
28.0  27.8  27.9 
26.6  26.8  26.  i 

33-8  34-5  34-0 
10.3     8.7   10.3 
9.0     9.2     9.2 
16.7  17.0  16.0 
ii.  2   ii  .2   10.9 

11.03 

7-93 
9.  10 
33.67 
25.20 
27.87 
18.73 
42.33 
19.17 
27.90 
26.50 
34-i° 
9.77 
9-i3 
16.57 

II  .  10 

11.07 
8.53 
9-44 
33-89 
25-85 
27.89 

18.95 

0.40 
o.  16 
0.24 
3-17 

2.22 
2-44 

i-47 

4-05 

7-56 
7-32 
7.40 

10.33 
9-38 
9.60 
8.63 

11.21 

7-83 
7-59 
7.67 
10.60 

9-65 
9.87 
8.90 
11.48 

1904  September  3.                                                                                Good;  twilight  at  beginning. 

18  24 
18  48 

34 
36 

37 
37 

Bai 
Cal 
C 
I 

fa 

2 
i- 

6 
a 

11 
a 
b 
s 

z 

I 

C 
B«. 

7.0     6.9     7.9 
15.3  16.0  16.3 
9.2   10.1     9.2 
8.0    8.0     7.7 
15.9  16.7  16.  i 
30.1  30.5  31.2 

21  .  I     21-5    21.8 
24.7    25.2    25.0 

17.2  17.7  18.1 
27.  I  27.2  27.8 
17.5  16.8  18.5 
26.2  26.9  26.8 
24.9  24.0  24.2 
32.5  32.2  32.1 
8.2     7.0    7.8 

IO.O      9.8    IO.2 

6.8     6.3     8.1 

7-27 
15.87 
9-50 
7.90 
16.23 
30.60 

21-47 
24.97 
17.67 
27.27 
17.60 
26.63 
24-37 
32.27 
7.67 

IO.OO 

7.07 

7.17 

0.07 

1.  06 
0.27 

O.  II 
I.  12 

2.85 

1  .92 

2.22 

I-3I 
2.38 

7-31 
8.30 
7-51 

7-35 
8.36 
10.09 
9.  16 
9.46 

8-55 
9.62 

7-58 
8.57 
7-78 
7.62 
8.63 
10.36 
9-43 
9-73 
8.82 
9.89 

9-75 
7-79 

31-44 
22.92 
25.80 
17.69 

1904  September  4.                                                                          Quiet;  stars  dull;  fair  measures. 

19  18 

19    22 

41 

43 
43 

C 
fi», 
I 
z 
i 
6 
a 
a 
6 
s 
z 

I 

Bai 
C 

13-3  14-3   H  2 
14.3  14.0  13.9 
12.9  13.3  12.8 

35-6  34-5  35-i 
28.6  29.2  28.8 
30.3  30.6  30.5 
24.2  25.2  24.5 
23.8  24.1   24.1 
28.7  29.0  29.8 
28.2  28.2  27.8 
37.0  36.8  36.4 
13.0  12.9  12.9 

13-7   '3-4  '44 
13.4  14.2  14.6 

13-93 
14.07 
13.00 

35.07 
28.87 

30-47 
24.63 

24.00 

29.17 
28.07 

36.73 
12.93 

13  83 
14.07 

14.00 

13-95 
12.97 
35-90 
28.47 
29.82 
24.32 

0.79 
0.78 
0.63 

3-45 

2    51 
2.67 
2.07 

7-49 

7.48 

7-33 
10.15 
9.21 

9-37 
8.77 

7.76 
7-75 
7.60 
10.42 
9.48 
9.64 
9.04 

76 


RESEARCHES    IN   STELLAR   PHOTOMETRY. 


TABLE  46. — 5798  RU  HBRCUUS.     PHOTOMETER  MEASURES  OF  COMPARISON  STARS. — Continued. 


1904  August  ii.                                             12-INCH.                                                                   Good. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6 

H. 

P. 

18     2 
18  28 

O 

29 
33 

m 
n 

11 

I 

e 
a 
b 

s 
z 
z 
s 

b 

a 
e 
h 

g 
n 
m 

54-8  54-3  53-5 
57-4  58-2  58.3 
34-5  35-8  35-4 
46.4  46.4  46.9 
48.3  47.8  47.3 
43.0  42.9  43.1 
15.0  14.9  14.8 
23.9  24.0  25.0 
18.5  18.7   19.2 
30.6  31.2  30.6 
31.8  31.1   31.5 

22.0    23.7    22.5 
23.1     23.5    23.8 

15.7   16.0  15.1 

42.O   42.0   42.  2 

48  .  i  49  .  2  48  .  4 
49-i  50.7  48.8 
55-J   55.7  56.0 
52.4  52.8  52.0 

54-20 
57-97 
35-23 
46-57 
47.80 
43-00 
14.90 
24.30 
18.80 
30.80 

31-47 
22.73 

23-47 
15.60 
42.07 
48.57 
49-53 
55  60 
52-40 

53-30 
56.79 

5  10 
5-33 

3-22 

4-63 
4-59 
4.06 
i.  08 

2.  IO 

1.80 

2.77 

12.55 
12.78 
10.67 
12.08 
12.04 
".51 
8-53 
9-55 
9-25 

IO.22 

12.82 
13.05 
10.94 

12.35 
12.31 
11.78 
8.80 
9.82 
9-52 
10.49 

48.05 
48.19 

42.52 
15-25 
23.89 
20.77 
31-14 

1904  September  8.                                                                               Fair  to  good;  quiet;  rather  dull. 

19  20 

19  47 

42 
47 

z 
s 

b 

a 
m 
n 

g 

•v 
h 
e 
e 
h 
•v 

g 
n 
m 
a 
b 
s 
z 

24.6  24.2  23.2 
16.9  16.8  15.9 
18.  i   18.6  18.9 

II  .8    12.2    12.4 

47.0  46.  i  46.2 
50.3  50.0  49.1 
40.0  40.6  40.6 
'7-8  '5-3  16-2 
43-7  43-i  43.6 
36.1  35-7  36.3 
37.2  36.8  36.9 
42.8  42.9  43.1 

'7-7   17-7   15-5 
41.1  41.1  40.3 
52.  i  50.0  51.  i 
45.2  46.2  45.3 

13-5    13-7     12-9 
21  .O    20.3    19.7 

16.0  16.4  16.8 
26.4  25.4  26.  i 

24.00 
16.53 
18.53 

12.  13 

46.43 
49.80 
40.40 
16.43 

43-47 
36-03 

36.97 
42-93 
16.97 
40.83 
51-07 
45-57 
'3-37 
20.33 
16.40 
25-97 

24.99 
16.47 
19.43 
12.75 
45.00 

50.44 
40.63 
16.70 
43.20 
36  50 

2.  2O 
1-25 
1-63 
0.76 

4-33 
4-85 
3-85 
1.29 
4.12 
3-37 

10.  13 

9.18 

9  56 

8.69 

12.26 
12.78 
11.78 
9.22 
12.05 
11.30 

10.40 
9-45 
9  83 
8.96 

12.53 
13  05 
12.05 

9-49 
12.32 

11-57 

1904  September  9.                                                                                                   Quiet;  quite  good. 

19    o 
19  27 

39 

44 

z 
s 

b 

a 
m 
n 

Tl 
g 

h 
e 
e 
h 

g 
•v 
n 
m 
a 
b 
s 
z 

30.0  30.0  29.8 
19.8  19.2   19.6 
23-2  23.5  23.2 
15.8   16.8  15.8 
51.5  51.4  50.8 
55-2  55-1   55-6 
19.6  18.8  19.8 
47.3  48.8  47.8 
50.0  49.2  49.2 
40.2  41.2  41  .9 
41  .0  41  .2  41  .6 
46.2  47.5  48.0 
47.0  47.6  47.3 
19.8  17.8  18.8 
54-0  55-8  57.1 
52.0  52.1  51.7 
15.2   15.8  15.5 
26.7  26.3  25.6 

22.2    21  .6    21.9 
30.6    30.5    30.0 

29-93 
19-53 
23-33 
16.13 

51-57 
55-30 
19.40 
47-97 
49-47 
41  .  10 
41.27 
47-23 
47-30 
18.80 
55.63 
51-93 
15-50 
26.20 
21.90 
30.37 

30-15 
20.72 

24-77 
15.82 

51-75 
55-47 
19.10 
47.64 

48.35 
41.19 

2.67 

i-79 
2.18 
1.17 
4.96 

5-25 
1.61 

4-59 
4  65 
3-91 

IO.  II 

9.23 

9.62 
8.61 
12.40 
12.69 
9  05 
12.03 
12.09 
"•35 

10.38 
9-50 
9.89 
8.88 
12.67 
12.96 
9-32 
12.30 
12.36 
ii  .62 

CHAPTER    VI. — RU    HERCUUS.  77 

TABLE  46. — 5798  RU  HERCUUS.     PHOTOMETER  MEASURES  OF  COMPARISON  STARS. — Continued. 


1902  March  5.                                                       40-INCH.                                                              Fair. 

Sidereal 
Time. 

Zen. 
Dist. 

Star- 

Scale  Readings. 

Hean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

p. 

'4  35 

h 

g 
n 
m 

P 

w' 
t' 

g 

h 

22.9  23.9  24.6 
22.5  21.8  23.0 
30.1  30.8  29.7 
24.8  25.0  24.7 
35-8  35-2  34-7 
45-3  45-4  45-0 
56.4  54.0  55.0 
23.2  23.3  22.8 
23.0  22.7  21.9 

23.80 
22.43 
30.20 
24-83 
35-23 
45-23 
55-13 
23.10 

22.53 

23-17 

22.72 

2.04 

2.00 
2.67 
2.18 
3-22 
4.36 
5.24 

12.  II 
12.07 
12.74 
12.25 
13.29 
I4.43 
I5.3I 

12.38 

12.34 
13.01 
12.52 
13.56 
14.70 
15.58 

1902  March  15.                                                                                                                   Clear;  unsteady. 

15  10 

h 

g 
n 
m 

P 

•w 

P 
m 
n 

g 
h 

30.0  30.2  31.5 
30.0  28.  i   28.7 

35-7  38.3  36.3 
34.8  34.0  34.0 
43.0  43.4  44.3 
59.2  60.0  59.0 
42.1  44.5  43.0 
33-5  34-2  33-4 
38.3  37-2  36.8 
31.1  32.3  30.0 
34-2  33-5  31-0 

30.57 
28.93 
36.77 
34-27 
43-57 
59.40 

43-53 
33-70 
37-43 
31.13 
32.83 

31-70 
30.03 
37-10 
33-99 

43-55 

2.83 
2.65 
3-45 
3-07 
4.  16 
5.46 

12.  12 
11.94 

12-74 
12.36 

13-45 
14-75 

12.39 

12.  21 
13.01 
12.63 
'3    72 
15    02 

1902  March  15.                                                                                                       Light  turned  down. 

n 
m 

$ 

t' 
t' 
w' 

P 
m 
n 

27.2  28.4  29.0 
26.8  24.5  25.3 
36.8  37.3  36.1 
47.8  48.8  48.0 
57.0  52.8  56.2 
53-3  54-7  54-0 
47-2  47-8  49-8 
36.2  34.2  34.8 
24-3  25.3  24.7 
30.8  27.4  29.2 

28.20 
25-53 
36.73 
48.20 

55-33 
54-00 

48.23 
35-07 
24-77 
29  13 

28.67 
25.15 
35  90 
48.22 
54.67 

2.52 
2.21 
3-29 
4-64 
5.20 

12.74 
12-43 
I3.5I 
14.86 
15.42 

13.01 
12.  70 
13.78 
I5-I3 
15    69 

1902  May  2.                                                                                         Seeing  good;  perhaps  variable. 

12  45 

h 

g 

« 
m 
Vaa 
t' 
TV' 
•w' 

t' 

Vat 
m 
n 

f 

27.4  30.1   29.9 
30.0  28.5  29.0 
27.  i   27.8  28.2 
33-2  33-5  34-4 
32.2  32.9  32.3 
15.7  16.5  17.3 
61.3  61.5  58.8 
55-3  55-0  55-3 
S3-1  53-o  52  9 
56.3  57-5  58.3 
16.0  16.1   15.2 

31  9  31-7  31-9 
34-8  35-0  37-2 
27.5  27.5  28.9 
28.1  29.1  30.5 

32.4  33-3  30.4 
31.0  30.9  30.4 

29.13 
29.17 
27.70 
33.70 
32.47 
16.50 
60.50 
55-20 
53-oo 
57-37 
15-77 
31-83 
35-67 
27.97 
29.23 
3I-I9 

30.  16 
29.20 
27.84 
34  69 
32.15 
16.  14 

58.94 
54-to 

2.67 
2-57 
2-45 
3-16 

2.88 

I.  21 

5-44 
5.16 

1  2.  2O 
12.  IO 

ii  93 
12.69 
12.41 

10.74 

14.97 
14.69 

12.47 

12-37 
I2.J5 
12.96 

12.68 
ii  .01 

15-24 
14.96 

RESEARCHES   IN   STELLAR    PHOTOMETRY. 


TABLE  47. — 5798  RU  HERCUUS.    CONSTANTS  FOR  REDUCTION  AND  COMPARISON  WITH  CATALOGUE 

MAGNITUDES. 


6-INCH. 

Star. 

1904    July  31. 

1904    September  3. 

1904    September  4. 

C. 

Obs.  Mag. 

4  Mag. 

C. 

Obs. 

Mag. 

A  Mag. 

C. 

Obs. 

Mag. 

J  Mag. 

H. 

P. 

H. 

P. 

H. 

P. 

H. 

P. 

H. 

P. 

H. 

p. 

B 
C 

I 

-0.59 
0.40 
o.  24 

6-57 
7-56 
7.40 

6.84 

7-83 
7.67 

•—  .  i 
+  .1 
—  .0 

i  -.04 
9  +.03 
8  —  .01 

-0.68 
o.  29 

O.2O 

6.56 
7-53 
7-44 

6.83 
7.80 

7-71 

—  .  12 

+  .16 
-  .04 

-  -05 
.00 

+  .03 

0.03 
0.79 
0.63 

6-73 
7-49 

7  •  33 

7 
7 
7 

.00 
.76 
.60 

+  .0; 

+  .1: 

-  -i; 

+  .12 
-  .04 
—  .08 

Means. 
M0.... 

O.O2 

7.18 
7.16 

7-45 
7-43 

±.i 

3  ±-03 

—  O.O6 

7.18 
7-24 

7-45 
7-51 

±.07 

±.03 

0.48 

7.18 
6.70 

7 
6 

•45 
•97 

±.ii 

±.08 

12-INCH. 

40-INCH. 

Star. 

Mag. 
6-inch 

C. 

Star. 

Mag. 
i2-inch. 

C. 

Sept.  9. 

\ug.  ii.    Sept.  8 

Mar.  5. 

Mar.  15. 

May  2. 

Mar.  15. 

8.65 
9.48 
9-25 
10.  19 

1.17 
2.18 

1-79 
2.67 

i.  08       0.76 
2.10        1.63 
i.  80        1.25 
2.77        2.  20 

ii 

12 
12 
12 

.96 

.06 

.40 

•75 

2  .OO 
2.O4 
2.18 
2.67 

2.65 
2.83 
3-07 
3-45 

2-45 
2-57 
2.88 
3.16 

b 

...:.  .. 

m 

n  . 

Me 
Me 
M0 

2.21 

2.52 

z   

in  C.  ... 

Meat 
Meat 
M 

1  C    ..  . 

i-95 

9-39 
7-44 

i  .  94        i  .  46 
9-39       9-39 
7-45        7-93 

2.22 
12.29 
IO.O7 

3.00 
12.29 
9.29 

2.76 
12.29 
9-53 

2.36 
12.58 
IO.22 

i  Mag. 

9-39 

in  Mag. 

12 

.29 

CHAPTER    VI. — RU  HERCULIS. 

TABLE  48. — 5798  RU  HERCULIS.    MEAN  MAGNITUDES. 


79 


6-INCH. 

Star. 

July  31. 

September  3. 

September  4. 

Mean. 

Mag. 

4  Mag. 

Mag. 

J  Mag. 

Mag. 

4  Mag. 

Mag.  H. 

Mag.  P. 

4  Mag. 

B  

6.57 
7-56 
7.40 

-0.05 
+  0.03 

4-O.OI 

6.56 
7-53 
7-44 

—  0.06 

O.OO 

+0.05 

6.73 
7-49 
7-33 

4-o.  ii 
—  0.04 
—  0.06 

6.62 
7-53 
7-39 

6.89 
7.80 
7.66 

±0.07 
±0.02 
±0.04 

C. 

1  

J 

Q, 

lean     

7.18 

7-45 

±0.04 

8.63 
9.60 
9-38 
10-33 

—  O.O2 
4-O.  12 
+  0.13 
+  0.14 

8-55 
9.46 
9.  16 
10.09 

—  0.  IO 
—  O.O2 

—  0.09 

—  O.  10 

8.77 
9-37 
9.21 
10.15 

4-o.  12 

—  O.  II 

—  0.04 
—  0.04 

8.65 
9.48 

9-25 
10.  19 

8.92 
9-75 
9-52 
10.46 

±0.08 
±0.08 
±0.09 
±0.09 

b  

s  

2  

1 

•lean  

9-39 

9.66 

±0.08 

1  2-INCH. 

Star. 

August  ii. 

September  8. 

September  9. 

Mean. 

Mag. 

A  Mag. 

Mag. 

JMag. 

Mag. 

J  Mag. 

Mag.  H.  Mag.  P.j  J  Mag. 

8-53 
9-55 
9-25 

10.22 

-0.08 
-0.03 
+  0.04 
+  0.07 

8.69 
9-56 
9.18 
10.13 

+  0.08 

—  O.O2 
—  0.04 
—  O.O2 

8.6: 
9.62 
9-23 

IO.  II 

O.OO 

4-0.04 
4-0.01 
—  0.04 

8.61 
9-58 
9.22 
10.15 

8.88 
9-85 
9-49 
10.42 

±0.05 
±0.03 
±0.03 
±0.04 

6  

s    

2           

! 

g 

Jean  

9-39 

9.66 

±0.04 

11.51 

12.08 
I2.O4 

12-55 
12.78 

+  O.  12 
4-O.  12 
—  O.O2 
+  0.15 
+  0.03 

11.30 

11.78 
12.05 
12.26 
12.78 

—  O.O9 

-0.18 

—  O.OI 

-0.14 
4-0.03 

"•35 
12.03 
12.09 
12.40 
12.69 

—  0.04 
4-0.07 
+  0.03 

O.OO 

—  0.06 

ii  39 
ii  .96 
12.06 
12.40 
12-75 

11.66 
12.23 

12.33 
12.67 
13.02 

±0.08 

±O.  12 
±O.O2 
±O.  IO 
±0.04 

:::::::::::::::::: 

m  

w  

J 

lean  

12.  II 

12.38 

±0.07 

4O-INCH. 

Star. 

March  5. 

March   15. 

March  15. 

May  2. 

Mean. 

Mag.      4  Mag. 

Mag. 

A  Mag 

Mag. 

A  Mag. 

Mag.  A  Mag, 

Mag.  H. 

Mag.  P. 

4  Mag. 

1::: 

m  .  . 
n.  .  . 

Mean 

f'-.V. 

TV'.. 
Mean 

12.07    +0.09 

12.  II           O.OO 

12.25    —  o.n 
12.74    +0.01 

"•94 

12.  12 
12.36 

12-74 

—  0.04 
4-0.01 

O.OO 
4-O.OI 

11.93  -0.05 

12.  IO  4-O.OI 

12.41  4-0.06 

1  2  .  69  —  0  .  04 

11.98 

12.  II 

12.36 

12.73 

12.25 

12.38 
12.63 
13.00 

±0.06 
±0.01 
±0.06 
±0.02 

12-43 
12.74 

4-0.07 
4-0.01 

12.30 

12.57 

±0.04 

13.29    -0.13 
15.31     +0.08 
14.43    -0.25 

13-45 
H-75 

+  0.03 
+0.07 

I3-5I 

15-42 
14.86 

4-0.09 
+  o.  19 
4-o.iS 

13-42 
15-23 
14.68 

13-69 
i5-5<> 
14-95 

±0.08 
±0.18 
±0.13 

14.97    —0.26 
14.69    4-0.01 

14.44 

14.71 

±0.13 

So 


RESEARCHES    IN    STELLAR    PHOTOMETRY. 


IS 


14.  /a 


MAGNITUDE 
AZ  // 


^f  i  ,  , 


i 


S798RU  HERCULIS 


Vf. 


In 


FIG.  1 6. — MAGNITUDE-CURVE  FOR  RU  HERCULIS. 


CHAPTER    VI. — RU   HERCULIS. 


8l 


TABLE  49.— 5798  RU  HERCULIS     VISUAL  OBSERVATIONS  OF  THE  VARIABLE. 


No 

Date. 

jj 

g 

C 

Aperture. 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing. 

/. 

J  Mag. 

Month 
and  Day 

Hour 
C.  S.T 

Julian 
Day 
G.  M.'T. 

Steps. 

Mag. 

i 

2 

3 
4 
5 
6 

7 
8 

9 
10 
ii 

12 

'3 
'4 
15 
16 

i? 
18 

'9 
20 

21 
22 
23 
24 
25 
26 

27 

28 

29 
30 

3' 

32 

33 

34 
35 
36 

37 

38 

39 
40 
4i 
42 
43 
44 
45 
46 
47 
48 
49 
50 
5i 
52 

1897 
Jan.      7 

May     5 

17 
25 
June     7 
20 
25 

J»iy    s 
17 

21 
23 

Aug.     3 
13 

14 

20 

Sept.    3 

12 
13 
'4 
21 

25 
29 

Oct.    14 
23 
29 
Nov.  1  1 
16 

I8q8 
Jan.      2 

18 

28 

Feb.    12 
Mar.     2 

23 
Apr.     i 
ii 
14 
25 

May     7 

ii 
16 

23 
June  14 

Jllly     5 
18 
26 
Aug.     8 
19 
27 
Sept.    7 
Oct.      5 
Nov.     i 

2 

18 
9 

9 
9 
9 
9 
10 

9 

9 
9 
9 
9 
9 
8 
8 

7 
8 
8 
8 
7 
7 
7 
6 
6 
6 

18 

18 

18 

18 
i? 
'7 

16 
9 
9 
6 

6 
10 
9 
9 
9 

10 
10 

10 
10 
9 
9 

8 

7 
6 
6 

2410000+ 
3933-00 

4050.63 

4062 
4070 
4083  63 
4096  .  63 
4101.63 
4111.63 
4123.67 

4127.63 

4129.63 
4140.63 
4150.61 
4151.61 
4I57-6I 
4171.58 
4180.58 
4181.54 
4182.56 
4189.56 
4193  56 

4'97-54 
4212.54 
4221.54 
4227.50 
4240.50 
4245-50 

4293.00 
4309.00 

4319.00 

4333-98 
435L96 

4372.96 
4381.92 
439I.63 
4394.63 
4405.61 

4417.63 

4421.65 
4426.63 
4433.63 
4355.63 
4476.67 
4489.67 
4497.67 
4510.67 
452i  63 
4529-61 
4540.58 
4568.54 
4595  •  50 
4596.50 

40 
150 

'50 
150 
150 
40 
ISO 
150 
80 

150 

80 
150 
'SO 
150 
15° 
150 
150 
150 
150 
'SO 

'SO 
150 
150 
15° 
'SO 

150 
150 
40 
150 
40 
40 

40 

40 
40 
40 
40 

40 

40 
40 
40 
80 
So 
So 
175 
'75 
80 

150 
150 
'50 
150 

6 
6 

6 
6 
6 
6 
6 
6 
6 

6 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

6 
6 
6 
6 
6 
6 

6 

6 
6 
6 
6 

6 

6 
6 
6 

12 
12 
12 
12 
12 
12 
6 
6 
6 

6 
6 

O4»,    7)26  

\cid,  die,  eo-if,  fo—ig.[ 

(  g2/Z     /I2—  3#       .  .                       ) 

25-7,  23-0  

24-3 
3-5 

<6 
<6 
<6 
<6 
<6 
<6 
<6 

-i-5 

<o 
<o 
<3 
<3 
<o 

<3 
<3 

<2 
<0 
<0 
<0 
<0 

—  1  .0 

0.3 

2.7 

3-4 

3-4 

3-1 

4-1 

ii  .  i 

20.  o 
26.2 

26.0 

25-4 
24-4 
23-9 

20.3 

18.6 

16.7 
17.1 

'7-3 
9.0 

8-3 
6-5 
6.1 

5-i 
5-i 
0-7 

I  .2 

-0.8 

<3 
<i 

9-17 
12-75 

<I2 
<I2 
<I2 
<I2 
<I2 
<I2 
<I2 

13-7 

<'3  3 
<i3-3 

<I2.8 
<I2.8 

<i3-3 

<I2.8 
<I2.8 

<I3  o 

<i3-3 
<i3-3 
<I3  3 
<i3-3 
13-50 
13.28 
12.89 
12.77 
12.77 

12.80 
12.64 

"-43 

9.92 

8.87 

8.90 

9.00 
9.  16 

9-25 

9.87 
10.  16 

10.50 
10.41 
10.37 
11.80 

"•93 
12.25 
12.30 
12.46 
12.46 
13.21 
13-15 
13-47 

<I2.8 
<I3-2 

good 
good 

fair 
good 
good 
good 
good 
fair 
good 

good 

good 
fair 
poor 
fair 
good 
moon 
moon 
fair 
good 
good 

0 

"7 
194 

—  O.  12 

+  0.26 
+  0.06 

eij,  jzh  

ei-zf.  }2h  

tfl-4/    fih 

jh±     

erf,  jih  

ei—2f,  }i—2h  

£2/,    flh     . 

/  g2m,  m,2n,  n^p       ....    ) 

p  glimpsed,  v  not  seen    .  .  . 

v  not  seen,  limit  p  

v  not  seen,  limit  n   

v  not  seen,  limit  n  

v  not  seen,  limit  p     

v  not  seen,  limit  n 

v  not  seen,  limit  m  or  n    , 

v  not  seen,  limit  i<ro.    .  .  . 

v  not  seen,  limit  p  

v  suspected,  vp?  

v  not  seen,  limit  3<n  

v  not  seen,  limit  3  <  n  

good 
good 

fair 
good 

good 
fair 

good 

good 
good 

good 

good 
good 
fair 

good 
good 

good 
fair 
fair 
fair 
fair 
poor 
fair 
good 
good 
poor 
fair 
fine 
fair 
good 

279 
288 
294 

307 
312 

360 
376 

386 

401 
418 

440 

449 

458 
462 

473 
i 

5 
10 

i? 
39 
60 

73 
81 

94 
105 
"3 
124 

152 

+  0.81 
+  0.88 
+  0.61 
+  0.74 
+  0.81 

+  1.50 
+  1-53 

+  0-53 
—  0.18 

+  0.  12 
+  0.39 

+  0.50 
+  0.53 
+  0.52 

+  0.90 
+  0.83 

+  1.08 
+  0.84 
+  0.64 

+  1-39 
+  0.72 
+  0.62 
+  0.47 
+  0.36 
+  O.  II 
+  0.78 
+  0.65 
+  0.50 

piv  

n2—  311,  limit  v    

vn±,  mi-  2V,  limit  v  

2.8,  2.6  .  .  . 

miv,  vin,  g4~5t>  
miv,  vin  

3-1.  3-8,  3-5  
ii  18 

miv,  vin,  gs-6u  
g3~4U,  vin  

3-1,  3-8,  2.5  

4.  C,  7.8  

i?3g,  di—2V,  qiv     

ii.  o,  ii.  6,  ii.  o  "* 

T770T 

v^x,  #40,  o6-8u    
uyv,  via,  114—56,  V&-IQX.  .  . 

u$v,  V2t,  va,  vi—2s,  1146  .... 

vis,  V2b,  ay>,  vt,  u^-^v.... 
tyv,  a^v,  vo—ib,  vs  

20.4,  17.1,  22.7  .  . 

23.5,  30.7,  25.5,  25.4 
(22.5,  28.7,  29.7* 

(  28  .  4,  250....  > 

527.9,  23.0,  26.  7\ 

1  26  7  21  O 

23.7.  25-7,  21.5,  26.9 

24.  O  2^  O 

J  S2V    V2b    642    Z$d                    ^ 

\_W2d,    Z^X     X$O,    .      .      .      .     ) 

)20.  7,19.0,  20.5  \ 
(21  .  4,2O.  I  / 

t6v,  b2V,  i>3y,  vyc,  v6~8d.  . 
(6511,  v^x,  1)2-32  ) 

\Z2X,    X2—^C,    X^—j^d       ...     ) 

16.0,  20.4,  19.  5  .  . 

'5-5.  15-5,  17-9,  18.0 
15.0,  17.0,  18.4,  18.0 
17.0,   18.4,   16.5 
10.0,  8.1  

65—  6V,    ZO—IT),    VI-2X,    t>4C.  .  . 

b6v,  vz,  V2x,  vyv,  X2W.  .  .. 

VZ,    V2X,    V2-y  
V2g,    6211  

ei,v,  fi-2g  
g2V,  vyn  
g2i>,  f  3-4n  
g2-3t>,  vin,  v6p      
g3V,  vn  v$-6p  
»13—  411,  limit  v,  m,2v    

m2—yv,    n2t>  

n4V,  po-iv  
v  not  seen,  limit  n  

7-',  9-5  
6.0,  7.1  
6.0,  6.3  
5.5,  3-8,  6.0  
5-5.  3-8,  6.0  

—  0.7,  2.1  

1.6,  0.8  

-1.2,  -0.5  

v  not  seen,  limit  i—  2<n.  . 

82  RESEARCHES  IN  STELLAR  PHOTOMETRY. 

TABLE  49. — 5798  RU  HERCUUS.    VISUAL  OBSERVATIONS  OF  THE  VARIABLE. — Continued. 


No. 

Date. 

Ocular. 

1 
1 
I 

< 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing. 

t. 

d  Mag. 

Month 
and  Day. 

Hour 
C.  S.  T. 

Julian 
"Day 
G.  M.  T. 

Steps. 

Mag. 

53 
54 
55 
56 
57 
58 
59 
60 
61 
62 
63 
64 

65 
66 

67 
68 
69 
70 
7i 
72 
73 
74 
75 
76 
77 
78 

79 

80 
81 

82 

83 

84 
85 
86 

«7 
88 

89 
90 

9" 
92 

93 
94 
95 
96 

97 
98 

99 

100 
IOI 

1  02 
103 
104 
105 

1899 
Jan.     8 
10 
Feb.   15 

Mar.     4 

'9 
Apr.     4 
16 
28 
May     4 
18 

29 
June    3 

13 

19 
23 
July     8 

17 
29 
Aug.     9 

17 
26 
Sept.    4 
20 
Oct.     4 

21 
28 

Nov.    6 

22 

Dec.   14 

1900 
Jan.      7 

26 
Feb.   1  8 

24 
Mar.     7 

21 

Apr.     4 
18 
May      i 

34 
June  13 

23 
July  21 

25 
Aug.  14 
Sept.  15 
Oct.    26 
Nov.  21 

1902 

Mar.     5 

Apr.  30 
May     2 
6 
Oct.     7 

18 
18 
'7 
J7 
17 
15 
15 
9 
9 
9 
9 
9 

9 

9 
9 
9 
9 
9 
9 
9 
8 
8 
7 
7 

6 
6 

6 

18 

17 
15 

13 
17 
15 
II 

15 

12 
10 

9 
9 
ii 

9 
10 

9 

7 
6 

H 
15 

7 

2410000+ 
4664  .  co 
4666  .  oo 
4701.96 
4718.96 

4733.96 
4749.92 
4761.88 
4773.63 
4779.63 
4793.63 
4804  .  63 
4809.63 

4819.63 

4825.63 
4829.63 
4844.63 
4853.63 
4865.61 
4876.61 
4884.61 
4893-58 
4902.58 
4918.54 
4932  •  54 
4949-54 
4956.50 

4965-  50  { 

4981.50 
5004.00 

5027.98 
5046  .  88 

5069.79 
5075-96 
5086.88 
5100.71 
5114.88 
5128.75 
5141-67 
5164.63 
5184.63 

5I94-7I 
5222.63 
5226.67 
5246.63 
5278 
53I9-54 
5345-50 

5814-83 
5824.88 
5870 
5872 
5876 
6030.54 

200 
200 
150 

150 
150 
40 
40 
40 
40 

40 
40 

40 

40 
40 
40 
40 

40 

40 
40 
40 
40 
40 
150 
150 
150 

200 

350 

350 
80 
275 
275 
275 
275 
275 
275 
350 
150 
ISO 
80 
15° 
15° 

237 
237 

237 
'67 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

6 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
•   6 
6 
6 
6 
6 
6 

6 

40 
40 

12 

12 
12 
12 
12 
12 
12 
40 

6 
6 

12 

6 
6 

6 

40 
40 
6 
40 
6 

12 

<5-5 
-'•3 
9.0 

12.0 

99 
14.4 

13-7 
12.9 

15-3 
'7-5 

22.8 

27.4 
30.0 

33-9 
34-9 
3'-3 
30.7 
28.5 
26.0 
25-5 
25-5 

21-7 

19.2 
16.8 
14.8 
14.0 

13.0 

10.8 
10.5 

4.6 

4-9 
0.9 
-0.8 

-2^6 
—  1.2 
-4.1 
-0.7 
—  2.1 
2-9 

1.8 
1.8 
i-9 
1-3 

3-2 

20.5 
18.7 

<I2.4 

13-58 
11.80 
II  .29 
ii  .67 
10.87 
10.99 

II  .  12 

10-73 
10.36 

9-44 
8-65 

8.20 

7-52 

7.36 

7-97 
8.07 
8.46 
8.90 
8.98 
8.98 
9  63 
10.08 
10.48 
10.63 
10.77 

II  .  10 

11.49 
"-53 

12-57 
12.50 

13.20 
13.48 
13.80 
13-78 
13-55 
14.04 

13-47 
13-71 
12.84 
13.01 
13.01 
13.0 
13.10 
12.79 
9-83 
10.13 

<8.3 
7-75 
9.2 
9.02 
9.48 
<n.6 

fair 
good 
good 
poor 
good 
good 
fair 
fair 
good 
good 
good 
good 

good 

fair 
good 
good 
good 
good 
fair 
good 
good 

good 
fair 
fair 
fair 

fair 

low 
fair 

good 

fair 
good 
good 
fair 
good 

poor 
good 
moon 
fair 
fair 
good 
good 
good 
good 
poor 

fair 
fair 

good 

250 
286 
303 
3i8 

334 
346 
358 
364 
377 
388 

393 
403 
409 

413 
428 

437 
449 
460 
468 
477 
3 
J9 
33 
50 
57 
66 

82 
105 

129 

148 

171 
177 
1  88 
202 
216 
230 

243 
266 
286 
296 

324 
328 

348 
379 
420 
446 

433 
443 
5 
7 
ii 

+  0.05 
—  0.67 
—  0.80 

—  O.20 

-0-55 
—  0.50 
—  O.2O 
-0.56 
-0.74 

-'•44 

—  2.  O2 

-1.66 

-1.82 
—  i  .64 
-0.51 

-0-33 
—  0.04 

+  O.2I 

+  o.  14 

—  O.  II 
+  0.24 
+  0.28 
+  O.2I 

—  o.  27 

-0-35 
-0.32 

-0-34 
—  0.69 

+  O.O2 
-0.38 

-0.17 
+  O.O2 
+  O.2O 
+  0.05 
-0.25 
+  0.27 

—  0.18 
+  0.63 
+  0.39 
+  0.79 

+  1.22 

+  i-3± 
+  1.63 
+  1.69 
+  i  .14 

+  1.65 

-o!68 

—  O.22 

-0.45 
—  O.I2 

b  i  v    HA.—  s,v 

—  i  .  o,  —  1.7  

jiv,  vig  
i?4g,  civ,  d2V  

VIS     dd.     $V     CAV     V2f  .. 

9.0,  9.0  
12.  o,  13.0,   ii  .  i 
9.0,  8.6,  10.0,  12.0 
14.  i,  15.4  

vi-zd,  xo-iv,  z6-?v  

14.6,  15.9,  10.5  .  . 
14.0,  11.9  

Vld,    VX,    ZI-2V  
V^d,    V2-T,X,    ZO-IV  

14.0,  16.4,  15.5  .  . 
17.1,  18.9,  16.5  .  . 

22.0,  20.5,  25.9  .  . 
24-5,  30.2,  25.0,  29.9 
32.7,  26.0,  30.9  I 
29.9  i 

33-4-  35-7,  3i-5 
36-4-  33-5  
33-4,  29.7,  31.0 
30.9,  28.0,  33.2 
26.9,  27.5,  31.2 
24.5,  29.7,  24.0  .  . 
27.2,  26.9,  22.5   .  . 

26.7,  22.  0,  27.9  .  . 

24.7,  19.5,  23.5,  19.0 

I7.O,  21.  0,  21.4,  17.5 

16.0,  17.4,  17.1  .  . 
13.0,  16.4,  15.1  .  . 
14.4,  13.6  
13.4,  14-1  t 

12.  I,  12.5  > 

1  1.  6,  10.0  

f  v\d    vs,b    v&s 

\  {4-59,  u2-3<  
liv,  v6a,  »5«  
V2l,  v6—Su  
liv    va    t>4~  52*  

/3~4»,  V2U,  1)3-40  

1"]—  8t>,    VIU,    VI-2O    

02-31),  vs,  vi-2b  
ay;,  vib,  vis  
a^v,  bi-2V,  vf>-^z,  vi~2a.  . 
b^v,  vif,  vyc,  va.  
ziv,  vtx,  1)40*  
241;,  vx,  V2d  
xiv,  vo-id,  v  very  red  .  .  . 
xzv,  vid  .  . 
div,  «4-5g  

dl—2V,    D2g  
V2~~  3Z 

7  O.  4.  I.  ^  8 

(g6v    vim    i?4»         .  .  .  .  1 

20  6  I,  6  8 

1  pn  u6-8w'  w'6t'   .  .   .  .  / 

—  0.2,  2.0  
—  O  2  —  I  '  5  .  . 

nyv,  V2p  
n$v    pi—  2V    limit  v        .    . 

n6v,  pi-2v,  v^w',  limit  w'  . 
n6v,  p2v  limit  2<v    

-32,  -1.5,  -3-5  . 
—  3-2,  —  2.O  

713-41),  p2-yo,  v6-8w'  .... 
nftv  p$v                           ,    .  . 

-0.7,  -2.5,  -0.5... 
—  T  2.  —  S  O  .  . 

nV~  4.V     V<£    . 

n6v,  piv  

—  3.2,  —  I  .O  

mil),  vn,  V2p  
niv    limit  v    

3.1,  2.8,  2.0  

«I1)4j     

niv    vsp 

i  8  20  

ni—2V    limit  v            .... 

g4D,  vn,  miv,  t>3/>?  
v$-6x,  v$z,  s6v,  62-31).  .  .  . 

62—  IV     V2—1X 

4.0,  2.8,  3.1,  3.0 

21.9,  22.O,  2O.9,  18.5 
ig  c  18  q  . 

photometer  

photometer  . 

photometer  

photometer  

photometer.        

photometer  

<IO 

CHAPTER    VI. — RU   HERCUUS.  83 

TABLE  49. — 5798  RU  HERCULIS.     VISUAL  OBSERVATIONS  OK  THE  VARIABLE. — Continued. 


No. 

Date. 

l_' 

Aperture. 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing. 

t. 

J  Mag. 

Month 
and  Day. 

Hour 
C.  S.  T. 

Julian 
Day 
G.  M.  T. 

Steps. 

Mag. 

106 

107 

1  08 
109 
no 
in 

112 

"3 
114 

116 
117 
118 
119 
1  20 

121 
122 
123 

124 

«25 
126 

127 
128 
129  • 

"30 

132 
'33 
134 
135 
136 
'37 
138 
'39 
140 
141 
142 
143 

1903 
May   17 
Oct.    ii 

1904 
May   14 
June     4 
6 
8 

July  31 

Aug.     2 
ii 

13 
26 
Sept.    2 

3 
8 
8 
9 
9 
Oct.    1  1 

1905 
Jan.    12 
Mar.   1  2 
26 
Apr.      i 

22 

May     2 
20 

June  20 

24 
26 
July     4 

23 
Aug.     6 

19 

22 

28 

Sept.  17 
Oct.    20 

22 

9 

7 

13 

12 
12 
12 

8 
9 
9 
9 

8 
8 

7 
S 

2410000+ 
6252.63 
6399-54 

6615.79 
6636.74 
6638.76 
6640  .  74 
6693.58 
6695  .  63 
6704.63 
6706.63 
6719.58 
6726.58 
6727-54 
6732-58 

67 
150 

40 

40 
67 
67 
67 
40 

67 
40 

6? 

12 

6 

6 
24 
24 
24 
6 

12 
12 
12 
6 
12 

6 
12 

24 
24 
12 

6 

6 
40 
40 
40 
40 
40 
40 
6 
40 

12 
12 
40 
40 
40 
40 
40 

6 
6 

12 
40 

V2C±  

i6± 

12.  0 

5-4 

10.  6± 
11.28 

12.40 

12.  3± 

n.  9± 
"-37 

II  .21 

10.  70 

10.67 
IO.76 
10.  DO 

9  75 
9.62 
9.22 

9-5± 
95 

7-72 

10.35 

fair 
good 

good 

387 
268 

-o.3± 
+  0.32 

—0.70 

giv,  vin  

7    O      78 

photograph   

photograph  

good 
good 
good 
good 
good 
moon 
good 
good 
fair 
fair 

fair 
good 

fair 

292 
345 
348 
357 
359 
372 
379 
380 

385 
385 
386 
418 

28 

-0-93 
—  0.29 

-0-77 
-0.65 

-0-49 
—  0.60 

-'•33 
-1-45 
-i-73 

-1-85 
—  i  .04 

+  0.27 

photograph  

photometer  

photometer  

photometer  

photometer  

Z2v,  ?'4<i  

16.0 

photometer  

photometer  

photometer  

photographs  

8 

18 
'3 
'3 

12 
IO 
12 
IO 

9 
II 

9 

IO 
10 
IO 

9 
9 

8 
8 
7 
7 
6 

6733 
6733 
6765.58 

6859.00 
6917.77 
6931-77 
6937-75 
6958-67 
6968.75 
6986.67 
6997.63 
7017.71 
7021.63 
7023.67 
7031.67 
7050.67 
7064.63 
7077.63 
7080.58 
7086  .  59 
7106.54 

7'39  54 
7141.50 

'67 
40 

40 
237 
237 
237 
237 
237 
237 
200 

237 
80 
300 
237 
237 
237 
237 
237 
150 
150 
80 
237 

photographs    ) 

/4«,  v6a  
v  is  1}  to  2*>g  

30.0,  35.7  
13.0,  19.0  

32.8 
17-5 

giv    g5~  6re 

7.0,  8  •? 

7-4 

7-2 

3-4 
3-5 
-0.7 
-0.8 
-1.6 
<3± 
-2.7 
0.4 

—  O.  I 

-0.6 

2-7 

'•5 
0.8 
6.9 

3-8 

5-8 

12.08 

12.  IO 

12-75 

12.74 

I3-46 
13.48 
13.60 
<I2.8 

13.80 
13-25 
13-37 
13-45 

12.88 
13  05 
13.20 
12.  l6 

12.69 
12.32 

fair 
fair 
good 
good 
good 
fair 
good 
poor 
good 
poor 
good 
fair 
good 
fair 
fair 
fair 
good 
fair 

106 
127 
137 
155 
1  66 
1  86 

192 
200 
219 

233 
246 
249 
255 
275 
308 
310 

—  0.26 

+  O.2O 
+  O.  12 
+  0.39 

+  0.17 

o.oo 

+0.13 
—  0.46 
—  0.42 

-0.27 

-o  71 
—  0.50 
-0.23 
-0.57 

+  0.66 
+  0.32 

gif    r>5» 

7078 

g5U,  miv,  vin  
gy>,  vn  

3.0,  3.1,  3.8  
5.0,  2.8  

n$v,  vp,  vio—i2iv'    .     .    . 

-2.2,    0.0,    (3.5)      . 
O.O,    —2.2,    —0.5    . 
-1.2,    -2.0,  (1.5).. 

g8v,  n^v,  po-iv    

n^v,  p2V,  r8—iow'  
v  not  seen,  limit  m  and  n   . 

n2—yv,  vSw'  

O3O5 

n2—  31),  v6—  8w'  

O    1      —  O    5 

—  1.2.    O    S 

t'o—  in,  m2v  

7721 

niv,  my!  

i  8    i   i 

n2V,  v  near  limit  

gi—  2V,  v$—  6n  .    ... 

6583 

gyi,  miv,  V2n  
g3~4t>,  V2m,  i>4«  

3.0,  3.1,  4.8  
4.5,  6.1,  6.8  

84 


RESEARCHES   IN    STELT,AR   PHOTOMETRY. 


§ 

* 


I 


10  § 


O 
O 


FIG.  1 7. — LIGHT-CURVE  OF  RU  HBRCUUL. 


CHAPTER  VI. — RU  HERCULIS. 

TABLE  50. — 5798  RU  HERCUUS.     MEAN  MAGNITUDE  FROM  40.25  DAY  GROUPS. 


Group  No  .... 
J    D     

i 
40 

2 
80 

3 

121 

4 
161 

5 

2OI 

6 

241 

7 
281 

8 
322 

9 

362 

IO 

402 

ii 
442 

12 
483 

3933   [    £ 
I   No. 

f        t 

0 

9.17 

—  O.  12 

I 

"7 
12-75 
+  0.26 

i 

88 

1  18 

194 

13-  7± 
+  0.06 
i 

279 
13-50 
+  0.81 
i 

25O 

300 
12.93 
+  0.76 
4 

102 

360 
12.80 
+  1.50 
i 

346 

388 

ti-33 
+  0.63 

3 
380 

429 
8.88 
+  0.26 

2 
418 

460 
9-32 

—  0.61 
4 

464 

«*  I  £ 

I   No. 

4899  -j     ^ 
L   No. 

r        t 

10.65 
+  0.96 

5 

18 
10.28 
+  0.24 
3 

58 
10.83 
-0.31 

3 

12.49 
+  0.57 
6 

94 
11.51 
-0.52 

2 

13  31 
+  0.58 

2 

138 
12.54 

-0.18 

2 

179 
'3  49 

+  O.O2 

3 

216 
13-79 

+  O.O2 

3 

13.58 
+  0.05 

I 

254 

13  59 

+  O.22 
2 

ii  59 
—0.56 

3 

291 
12.92 
+  0.59 

2 

10.99 
—  0.42 
3 

333 
13-04 
+  1-38 
3 

9.80 
-1.18 

4 

379 
12.79 
+  1.69 
i 

7.82 
-I.I9 

5 

420 
9-83 
+  i.  14 
i 

433 

8.83 
+  0.05 
4 

446 
10.13 
+  1-65 

i 

443 

M 

8  •?  + 

7  ,  7C 

5382   \     JM- 

-0.68 

No 

i 

i 

r        f 

g 

-587 

I       M 

924. 

to.  6± 

5865  j     JM 

—  0.30 

L   No 

i 

r      < 

•1 

268 

2Q2 

352 

380 

418 

11.28 

12.40 

11.^7 

10.58 

9.65 

7.72 

6348   j     ^M 

4-n    12 

—  O   7O 

—  O    Q"* 

—  0.55 

—  i  .39 

—  i  .04 

t    No 

I 

I 

I 

4 

5 

i 

r     t 

28 

J       M 

683'    j     JM 

(.    No 

r    / 

Means]    ^ 
L  No. 

H 
9.61 

+  0.21 
13 

54 
ii  .06 

0.00 

4 

IOO 
12.25 
+  O.  IO 

9 

138 
12.62 
+  0.20 

4 

1  86 
13.60 
+  0.04 
4 

2l6 

13-79 

+  O.O2 

3 

263 
I3-27 
+  O.  IO 

5 

296 
12.  19 
+  0.04 
IO 

348 
11.71 
+  0.48 
ii 

38i 
11.03 

—  O.II 

14 

424 
8.56 

—  O.2I 
IO 

456 
8.63 
+  0.41 

IO 

TABLE  51. — 5798  RU  HBRCULIS.     OBSERVED  MAXIMA  AND  MINIMA. 

Elements  of  maximum.     1898  March  6  O.  D.  24143S5)+483<1  E.     M  -  m  =  217*. 


MAXIMA. 

MINIMA. 

t 

W 

Date. 

Mag. 

Corr. 

Wt. 

J3 

1 
W 

Date. 

Mag. 

Corr. 

Wt. 

Calendar. 

J.  D. 

H. 

P. 

Calendar. 

J.  D. 

H. 

P. 

i 

2 

3 
4 
5 
6 

1898  Mar.  13 
1899  June  23 
1900  Nov.    2 
1902  Mar.  ii 
1903  June  28 
1904  Oct.  16 

4362 
4829 
5326 
5820 
6294 
6770 

8.85 
7-40 
9-77 

9.  12 

7.67 
10.04 

me 
me 
7-97 

+   7 
-   9 
+   5 

+  10 

+   7 

0 

'3 
16 

7 

2 

3 

12 

i 

2 

3 
5 
6 

1897  Aug.  30 
1898  Nov.    9 
1900  Apr.    15 
1902  Nov.  26 
1904  Feb.   28 

4167 
4603 

51^5 
6080 
6540 

13.90 
13-70 
13.86 

14.17 
13  97 
I4-I3 
me 
14.0 

+  29 
-18 

+  21 
+  10 

-13 

IO 

25 
23 
i 
6 

13-7 

86 


RESEARCHES   IN   STEU,AR   PHOTOMETRY. 


zoo 


30O 40O SOO 


5798  RUHERCULIS 

Max    «•  435 
Min..   . 


10 


kl 

a 
" 


FIG.  1 8. — MEAN  LIGHT-CURVE  OF  RU  HERCULIS. 


CHAPTER  VII. 


6100  RV  HERCULIS. 
R.  A.  i6l»  56"»  45»;  Dec. +  31°  22'  18"  (1900). 

This  variable  was  also  discovered  by  Anderson,  and  observations  began 
immediately  after  the  receipt  of  the  announcement  in  1897.  It  was  then  rapidly 
fading  and  passed  below  the  limit  of  the  6-inch,  October  i,  and  remained  below 
that  limit  till  1898  January  18.  The  following  maximum  was  well  fixed  as  1898 
March  15,  at  magnitude  10.50  on  the  Harvard  scale.  The  succeeding  minimum 
was  observed  with  the  12-,  24-,  and  4o-inch  telescopes,  the  last  by  the  courtesy 
of  Professor  Barnard.  The  four  following  maxima  were  well  covered  by  observa- 
tions, and  the  minima  of  epochs  4,  5,  and  12;  with  sufficient  comparisons  in 
the  intervening  time  to  make  sure  of  the  number  of  the  epoch,  and  to  give  some 
idea  as  to  how  closely  the  star  was  following  the  mean  light-curve. 

The  positions  of  the  variable  and  the  brighter  comparison  stars  were  measured 
with  the  6-inch  in  August,  1897,  the  fainter  stars  (those  with  the  Greek  letters, 
also  k  and  P)  were  measured  with  the  4O-inch  in  June,  1900. 

The  photometric  measures  of  the  stars  brighter  than  the  rath  magnitude 
are  more  closely  accordant  than  usual,  the  fainter  stars  less  accordant.  The 
difference  between  the  Harvard  and  Potsdam  systems  for  the  three  standard 
stars  used  is  0.25,  which  is  just  the  mean  of  the  magnitude  difference  for  the 
twelve  fields  considered. 

TABLE  52. — 6100  RV  HERCULIS.    STANDARD  MAGNITUDE  STARS. 


1900. 

Magnitude. 

Residuals. 

Star. 

B.  D.  No. 

R.  A. 

Dec. 

Color 
P.  DM. 

Catalogue. 

Measured. 

From  Cats. 

3 
Nights 

H.C.O. 

P.  DM. 

H. 

P. 

H. 

P. 

inter 

se. 

o 

-    h   m      s 

0               / 

B 

+  29  2924 

16  58  36 

+  29  26.0 

W  + 

7-5' 

7.92 

7.68 

7-93 

+  '7 

+  i 

±4 

F 

+32  2835 

16  58  31 

+  32  02.  o 

WG 

6-34 

6.62 

6-37 

6.62 

+   3 

o 

±5 

G 

+  31  2967 

17    04    12 

+  31     20.4 

WG- 

6.61 

6.66 

6.41 

6.66 

—  20 

o 

o 

Means 

6.82 

7.07 

6.82 

7.07 

±13 

0 

±3 

TABLE  53. — COMPARISON  STARS  IN  B.  D.  CATALOGUE- 


B.  D. 

1855- 

star. 

No. 

Mag. 

R.  A. 

Dec. 

- 

o 

h  m    s 

o     / 

b 

+  31  2949 

9.2 

16  54  49 

+  31  18.6 

e 

+  3'  295» 

8.6 

16  55  58 

+  31  26.8 

87 


88 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABLE  54. — COMPARISON  STARS  FOR  RV  HERCULIS  (IN  ORDER  OF  RIGHT  ASCENSION). 


Star. 

Coordinates  from  Variable. 

Light 
Scale, 
Steps. 

Magnitude. 

R.  A. 

Dec. 

Measured. 

From  Curve. 

H. 

P. 

H. 

P. 

/ 
r 
n 
u 
f 

b 

« 
a 
i 

Y 

m 
s 
k 
P 

a 

I 

0 

I 
d 

w 

X 

P 

t 
1 

e 

ft 

-346 
-301 
—  184 
-150 
-147 

—  146 
-137 

—  122 

-"3 
-   86 

-   76 
-   67 
+   88 
+  104 
+  H3 

+  133 

+  133 
+  176 
+  181 
+  186 

+  34° 
+  366 

+  344 
+  498 

+  727 

i- 
-27.0 

-23.5 
-14.4 
-11.7 
-"•5 

-11.4 
-10.7 

-   95 

-   8.8 

-   6.7 

-   5-9 
-   5-2 
+   6.9 

+    8.2 

+   8.8 

+  10.4 
+  10.4 
+  13.7 
+  14.4 
+  14-5 

+  26.6 
+  28.6 
+  26.9 

+  38.9 
+  56.8 

rt 
+  92 
+   32 
+  283 
-332 
-   52 

—  461 
+   46 
+  69 
+  128 
+   49 

+  396 
-154 
+   35 
+  44 
+  176 

+     4 
+  247 
+  475 
+  527 
—  422 

-475 
+  151 

—  212 
+  III 
+    56 

37-2 
33-3 

10.86 
ii  .67 

"•'2 
II.9 

35-8 

IO.O 

44.6 

12.28 
>4-75 

9.89 

12.  53 

15  oo 
10.  14 

15-7 

14.26 

14.51 

27-3 
8.5 
14-5 

12.67 
15.50 
14-95 

12.92 

15.75 
15.20 

11.4 
33-4 
25.3 
39-8 

15-22 
ii  .46 

10.67 

15.47 
11.71 

10.92 

13.  o± 

II  ,O± 

12.  O± 
12.25 
12.91 

11.48 

i3-3± 
»'.3± 

12.  3± 
12.50 
13.  16 
"•73 

3°  3 
26.0 
35-0 
51-2 

8.86 

9.11 

TABLE  55. — 6100  RV  HERCULIS.    PHOTOMETER  MEASURES  OF  COMPARISON  STARS. 


1904    July  31.                                                 6-INCH.                                                                     Fine. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

h    m 

-> 

17  38 

13 

F.i 

8.0     9.3     8.9 

8.70 

9.89 

O.27 

7-14 

7-39 

e 

21  .O    21-4    21.2 

21  .20 

22.22 

J-85 

8.72 

8-97 

d 

40.8    41.3    4I.I 

41.07 

40.64 

3-91 

10.78 

11.03 

) 

44-2  43-7  44-i 

44.00 

43-40 

4.14 

ii  .01 

n  .26 

b 

31.9  31.2  31.2 

31-43 

31.72 

2.89 

9.76 

10.  OI 

B 

14.0  14.5  13.8 

14.  10 

14-35 

0.83 

7.70 

7-95 

17 

Bai 

19.0  19.3  18.3 

18.87 

19.32 

I-5I 

8.38 

8.63 

Gai 

9.8     9.2   10.0 

9.67 

IO.O2 

O.29 

7.16 

7-41 

I  e 

Ga 

10  7     98   10.6 

IO-37 

19    2    19.9    2O  .  2 

19.77 

B 

15.0  14.2   14.6 

14.60 

b 

•31    7    -33    ^    "^2.1 

32  .03 

I 

41    O   4.2  .  2    4.1  .  2 

42.80 

'd 

39  .  2  40  .  8  40  .  6 

4O.2O 

27    7    2?.    1    22.7 

23.  23 

18     4 

18 

Fa, 

II  .  I     11.2     10.9 

II  .07 

STELLAR  PHOTOMETRY. 
+  im 


N 


PLATE  7. 


• 


•  +  2O 


2950 


d." 
.1 


.7 
a 


© 


o' 


•  w 


I.  • 


Scale,  i  mm  =  i3*.8. 


I 


6100  RV  HERCULIS. 
R.  A.  i6h  56"  44s.7>     Dec.  +31°  22'  18",  1900. 


1904  July  i. 


CHAPTER  VII. — RV   HERCUUS. 


89 


TABLE  55. — 6100  RV  HERCUUS.     PHOTOMETER  MEASURES  OF  COMPARISON  STARS. — Continued. 


1904    September  4.                                           6-INCH.                                                      Fair,  quiet,  dull. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

h   m 
19  26 

19  45 

O 

32 

34 
35 
33 

36 
35 

36 

F0. 
e 
d 

t 
b 
B 
Ga\ 
Gai 

B 
b 

d 
e 
F0. 

9.1   10.1   10.1 
23.9  24.1   24.4 
44.9  43.4  44.2 
45.8  46.1  45.1 
32.5  31.6  31.4 
15.9   16.1    15.1 
11.7   11.9  ii  .6 

12.  I    II  .2    12.2 

16.3  15.9  16.0 

32-1    3'-5    32-2 

45-4  44-3  45  2 
46  .  i  46  .  2  46  .  3 
26  .  2  26  .  7  26  .  i 
11.7   11.9  11.9 

9-77 
24-13 
44-17 
45-67 
31-83 
I5-70 
u-73 
11.83 
16.07 
31-93 
44-97 
46.20 
26.33 
11.83 

10.80 
25-23 
45-19 
45-32 
31-88 

15-89 

11.78 

o.37 
2.16 

4-3i 
4-32 
2.91 
1.07 
0.48 

7-05 
8.84 
10.99 
ii  .00 
9-59 
7-75 
7.16 

7-3° 
9.09 
ii  .24 
11.25 
9.84 
8.00 
7-4' 

1904    September  5.                                                                                             Good,  somewhat  dull. 

18  40 
19     i 

24 

26 

27 
27 

28 
28 

28 

Fa. 
e 
d 

b 
B 

Gai 
Gai 

B 
b 

fd 
e 
Fa. 

9.2     9.7     9.0 

22.  O    22.3    22.9 

40-9  4i-3  4'-5 
43-i   43-2  42-5 
29.7  29.9  29.8 
13-3  H-O  "3-9 
9-3     9-9     9-3 

IO.O      9.8    IO.2 

13-5   13-3  '3-4 
29.0  28.6  28.8 

42-3  43-0  42-9 
39.8  40.7  40.9 

21.9    22-4    22.  2 
10.5    10.2    10.  I 

9-3° 

22.40 

41-23 
42-93 
29.80 

13-73 
9-50 

IO.OO 

13-40 
28.80 

42.73 
40.47 

22.  17 
IO.27 

9-79 
22.29 
40.85 
42.83 
29.30 

13.57 
9-75 

0.28 
1.86 

3-93 
4.11 
2.62 

0.73 
o.  26 

7-18 
8.76 
10.83 
ii  .01 
9-52 
7-63 
7.16 

7-43 
9.01 
11.08 
ii  .  26 

9-77 
7.88 

7-4i 

1904    August  ii.                                               12-INCH.                                                               Good. 

18  42 

18  53 
19     7 

19   18 

23 

25 

28 

29 

b 

u 
r 

i 

s 

0 

d 
e 
e 
d 
o 
s 

f 
r 
u 
b 

27-5    27.5    26.6 
52.4    51-5    52.5 

43.2  44.3  43-7 
36.7  37-1   37-2 
55-9  57-0  56-4 
41.9  42.2  43.0 
35  9  36-7  36-1 
18.2   17.6  17.4 
18.2   18.1    17.5 
35-9  35-9  35-7 
42-9  43-3  43-2 
57-5  57-7  57-2 
37-7  38-9  38-2 
44-o  45-5  44-9 
51.3  51.2  51.1 
29.3  28.2  28.8 

27.20 
52.13 

43-73 
37-oo 

56.43 
42-37 
36-23 
17-73 
'7-93 
35-83 
43-13 
57-47 
38-27 
44.80 
51.20 
28.77 

27.99 
51-67 
44-31 
37-64 
56.95 
42-75 
36-03 

17-83 

2-45 
4.96 

4-25 
3-50 
5-35 
4.07 

3-3' 
'•43 

9-85 
12.36 
11.65 
10.90 

12.75 
11.47 
10.71 
8.83 

10.09 
12.60 
11.89 
ii  .  14 

12-99 
11.71 
10.95 
9.07 

90  RESEARCHES  IN   STELLAR  PHOTOMETRY. 

TABLE  55. — 6100  RV  HERCULIS.     PHOTOMETER  MEASURES  OP  COMPARISON  STARS. — Continued. 


1904    August  13.                                                   12-INCH.                                                             Good. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings- 

MeanScale  Readings- 

c. 

Magnitude. 

Mean  of  3. 

Mean  of  6- 

H. 

p. 

h    m 
19  38 

19  58 

O 

33 

37 

b 
u 
r 

} 
s 
o 
d 
e 
e 
d 
o 
s 

! 

r 
u 
b 

3i-3  32.5  32-4 
56.7  56.1   55.9 
49.0  48.4  49.7 
42.5  41.6  42.2 
60.  i  59.0  58.7 
45.8  46.5  48.0 
40  .  o  40  .  i    39  .  6 
20.1    20.3    19.2 
20.4   19.8  20.  6 

37-i   38-3  38.5 
44-8  45.9  45.0 
57.6  59.2  60.3 
39-9  40.9  40.2 
47  .0  48.9  48.  2 
57.8  56.8  57.0 
33.0  32.8  33.6 

32.07 
56.23 
49-03 
42.  10 
59-27 
46.77 
39-90 
19.87 
20.  27 
37-97 
45-23 
59-03 
40.33 
48.03 
57-20 
33-13 

32.60 
56.72 
48.53 

41  .22 

59-15 
46.OO 

38.94 
2O.O7 

2-93 
5-33 
4-67 
3-9« 
5-45 
4.42 
3  65 
1.72 

9  95 
12.35 
ii  .69 
10.93 
12.47 
11.44 
10.67 
8-74 

10.  19 

12.59 

"•93 
11.17 
12.71 
11.68 
10.91 
8.98 

1904    September  8.                                                                                              Quiet,  dull,  fair  to  good. 

20  35 

21       O 

44 

b 
u 
r 

f 
s 
o 

d 

e 
e 
d 

0 

s 

i 

r 
u 
b 

20.  i   20.9  20.7 
41  .9  42.6  41.8 
38.6  39.2  38.4 
29.8  30.7  30.2 
48  .  3  48  .  i  48  .  2 
37-3  37-2  38.0 
29.7  29.4  29.8 
14.0  14.7   15.0 
15.2   14.4  15.0 
30.5  29.2  30.2 
36-2  37-3  38.0 
51.1  50.2  49.8 
30.8  32.8  32.1 
38.5  40.6  39.5 
45.0  44.1  44.0 

22.9    22.9    22.  I 

20.57 
42.  10 

38-73 
30-23 
48.20 
37-50 
29-63 
14-57 
14.87 
29.97 
37-17 
50.37 
31.90 

39-53 

44-37 
22.63 

21  .60 
43-24 
39-13 
31-07 
49.29 
37-32 
29.80 
14.72 

1.88 

4-13 
3-68 
2.76 
4.78 
3-46 
2-63 
i  .01 

9.88 
12.13 
11.68 
10.76 
12.78 
ii  .46 
10.63 
9.01 

IO.  12 

12.37 
II  .92 
II  .00 

13.02 

II  .  70 

10.87 
9-25 

1900    June  8                                          40-INCH,  WEDGE  II. 

12  45 
13   15 

P 
s 
ft 
i 
r 

50  .  9  46  .  8  47  .  2  48  .  i 
28.1   28.  i   26.2  29.5 
47.1  44.3  46.5  44.6 
40.9  41.7  40.0  42.3 

21  .O    2O.  2    2O.  8    21  .5 

48-25 
27.98 
45-63 

41-23 
20.88 

4.82 
2.62 

4-57 
4.07 
1.63 

14-87 
12.67 
14.62 

14.  12 

11.68 

15.12 
12.92 

14.87 
14-37 

"-93 

1900  July  12. 

18  45 

s 

V 

1 

/ 

r 

a 
O 

27.O    24.0    26.O    29.3 
24.4    24.1    23.9    25.0 
44.0   43.9   41.8    43.7 
12-5    13.8    15.2    14.1 
22-4    21  .  I    21  .7    2O.9 
32.2    32.0   32.2    34.2 

20.4  20.  8  22.8  20.  o 

26.58 
24-35 
43-35 
13.90 

21-53 
32-65 

21.  OO 

2-45 
2.14 
4-32 
0.52 
1.74 
3-iS 
1.67 

12.52 

12.21 
14-39 

10-59 
11.81 
13.22 
11.74 

12.77 
12.46 
14.64 
10.84 
12.06 

13-47 
11.99 

CHAPTER   VII. — RV   HERCULIS. 


TABLE  55. — 6100  RV  HERCUUS.     PHOTOMETER  MEASURES  OP  COMPARISON  STARS. — Continued. 


1900    August  30.                                           40-INCH,  WEDGE  II. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

h    m 
19     6 

19  46 

/ 
r 

s 
i 
P 
k 
P 
i 

0 

1 
0 
ft 

P 

S 
s 
r 

f 

8.0  14.2   13.2 
23.4  22.5  23.0 
26.5  27.5  26.3 

55-5  54-4  53-5 
51.3  50.9  50.7 

57-3  57-8  59-i 
45.8  48.2  48.0 
45.0  44.8  44.2 
53-8  53-2  50.9 
41.8  43.5  42.2 

46  .  I    48  .  2    47.O 

53-1  55-2  56.9 
50.8  48.8  50.2 
52.6  52.9  53.0 
27-3  26.5  25.6 
18.  i    18.6  21  .0 
12.9   16.5   15.0 

11.80 
22.97 
26.77 
54-47 
50-97 
58.07 

47-33 
44.67 
52-63 
42.50 
47.10 
55-07 
49-93 
52.83 
26.47 
19.27 
14.80 

13-30 

21  .  12 
26.62 
53-65 
50-45 
56.57 
47-22 

43-59 

o  45 
1.70 

2-47 
5-23 

5-02 

5-45 
4-73 
4-35 
5-17 

10.64  ' 
11.89 
12.66 
15-42 
15.21 
15-64 
14.92 

14-54 
15-36 

10.89 
12  .  14 
12.91 
I5.67 
I5-46 
15.89 
15.17 
14-79 
I5.6I 

1900    September  13.                                                                                         Air  quiet,  seeing  good. 

19     6 

19  45 

1 

u 
s 

} 

r 

ft 

e 

0 

n 

a 
0 
i 
P 
k 
P 
S 
V 
0 
a 

1 
P 

r 

1 

s 
u 

23.8    24.4    22.  O 
26.2    27.1     27.3 

15.8  16.8  16.8 

2O.  8    21.5    22.  2 

46  .  i  46  .  2  47  .  i 

48  .  2     

49  2   

23.40 
26.87 
16.47 

21  .  50 
46.47 
48.2 

49-2 
40.50 

32.13 
19.60 
50.90 
46.83 
55.67 
49-03 
50.60 
46.90 

'9-43 
31.90 
40.50 
48.50 
22.83 

17.57 
29.27 

25.73 

24-57 
28.07 
17.02 
22.17 
47-49 

2.18 
2.64 
1.03 
1.83 
4-75 
4-8± 

4-9± 
4.00 
3.10 
'•43 
5-04 
4.80 

5-4° 

12.15 

12.  6l 

II  .00 
11.80 
14.72 

14.  8± 
14.  9± 
13-97 
13-07 
II  .40 
15.01 
14-77 
15-37 

12.40 
12.86 
11.25 
12.05 

H-97 
i5-0± 

15-  1± 
14.22 

13-32 
11.65 
15-26 
15.02 
15.62 

40.50 
32.01 
19-51 
50.75 
47-93 

40-5  41-5  39-5 
31.0  32.2  33.2 
20  .  o  1  8  .  8  20  .  o 

48.5  51-9  53-2 
46.8  46.2  47.5 
54-9  57-0  55-i 
48.9  49.9  48.3 
50.2  50.4  51.2 
45  .  9  46  .  o  48  .  8 
20.  i    18.2  20.  o 

31-9  3i-5  32-3 
40.2  40.3  41  .0 
48  .  i  48  .  9  48  .  5 
21-5  23.9  23.1 
18.9  17.6   16.2 
30.0  28.8  29.0 
25.5  26.5  25.2 

4.70 

14.67 

14.92 

RESEARCHES  IN  STELLAR  PHOTOMETRY. 


TABLE  56. — 6100  RV  HERCUUS.     CONSTANTS  FOR  REDUCTION   AND   COMPARISON   WITH  CATALOGUE 

MAGNITUDES. 


6-INCH. 


1904   July  31. 


1904  September  4. 


1904  September  5. 


Star. 


C. 


Obs.  Mag. 


H.        P. 


Mag. 


H. 


P. 


C. 


Obs.  Mag. 


H.        P. 


A  Mag. 


H. 


C. 


Obs.  Mag. 


H. 


P. 


J  Mag 


H. 


P. 


B 

F 

G 


0.80 
-0.48 
-0.46 


7.67 
6-39 
6.41 


7.92 
6.64 
6.66 


+  .16 
+  •05 
—  .20 


Means. 
M.. 


—  0.05 


6.82 
6.87 


7.07 
7.12 


.00 

+  .02 
.OO 

±.01 


1.07 
-0.38 
-0.27 


7-75 
6.30 
6.41 


8.00  +  .24 
6.55!-  -04 
6 . 66  -  .  20 


+  .08 
-.07 


0.73 
-0.47 
-0.49 


7.63 
6-43 
6.41 


6.68 
6.66 


+  .12 
+  .09 
—  .20 


-  .04 

+  .06 

.OO 


o.  14 


6.82 

6.68 


7.07  ±.16 
6  93       • 


±.05 


—  0.08 


6.82 
6  90 


7.07 
7-15 


±•14 


±.03 


12-INCH. 


40-INCH. 


Star. 


Mean  C .  .  .  . 
Mean  Mag. 


Mag. 
6-inch. 


9.62 
10.87 

8.77 
ii  .01 


10.07 


C. 


Aug.  ii.  Aug.  13.  Sept.  8 


2-45 
3  3i 
i-43 
3-50 


2.67 

10.07 

7.40 


2-93 
3.65 
1.72 

3-91 


3.05 

10.07 

7.02 


Star. 


1.88 
2.63 

I.OI 

2.76 


2.07 

10.07 

8.00 


Mean  C  . . 
Mean  Mag 

Mn. 


Mag. 
i  2-inch. 


10.86 
11.46 
it  .67 
12.67 
12.28 


C. 


June   8.  July  12.  Aug.  30.  Sept.  13 


i  63 
2.62 


2.  12 
12.17 
10.05 


0.52 
!.67 
'•74 
2-45 


I. 60 
II  .67 
IO.O7 


0.45 

1.70 

2.47 


1-54 

"•73 
10. 19 


1.03 


2.64 
2.18 


i  .92 

11.87 

9-95 


CHAPTER   VII. — RV   HERCUUS. 


93 


TABLB  57.— 6100  RV  HERCUUS.    MEAN  MAGNITUDES  OF  COMPARISON  STARS. 


6  INCH. 

Star. 

July  31. 

Sept.  4. 

Sept.  5. 

Mean. 

Mag. 

A  Mag. 

Mag. 

J 

Mag. 

Mag. 

A  Mag. 

Mag.  H. 

Mag.  P. 

A  Mag. 

B 

7.67 
6  39 
6.41 

—  O.OI 
+  O.O2 

o.oo 

7-75 
6.30 
6.41 

+  0.07 
—  0.07 
O   OO 

7-63 
6-43 
6.41 

—  0.05 
+  0.06 
o.oo 

7.68 

6-37 
6.41 

7-93 
6.62 
6.66 

±0.04 
±0.05 
o.oo 

F 

G    

Mean  

6.82 

7.07 

±0.03 

b.  . 

9.76 
10.78 
8.72 
ii  .01 

+o.  14 
—  0.09 
—0.05 
o.oo 

9-59 
10.99 
8.84 
ii  .00 

—  0.03 

+  O.I2 
+  O.O7 
—  O.OI 

9-52 
10.83 
8.76 
ii  .01 

—  O.  IO 

—  0.04 

—  O.OI 

o.oo 

9.  62 
10.87 

8.77 
ii  .01 

9.87 

II  .  12 
9.O2 
II  .26 

±0.09 
±0.08 
±0.04 

0.00 

d 

e 

/.  . 

10.07 

10.32 

±0.05 

12-INCH. 

Star. 

Aug.  ii. 

Aug.  13. 

Sept.  8. 

Mean. 

Mag. 

JUag, 

Mag. 

J 

Mag. 

Mag. 

A  Mag. 

Mag.  H. 

Mag.  P. 

A  Mag. 

j,                   

9-85 
10.71 
8.83 
10.90 

—  0.04 
+  0.04 
—  0.03 

+  0.04 

9-95 
10.67 

8-74 
10.93 

+  0.06 
o.oo 

—  O.  12 
+  0.07 

9.88 
10.63 
9.01 
10.76 

—  O.OI 

—  0.04 

+0.15 

—  O.IO 

9.89 
10.67 
8.86 
10.86 

10.  14 
10.92 
9.11 
ii.ii 

±0.04 
±0.03 
±o.  10 
±0.07 

j              

/  

Mean  

10.07 

10.32 

±0.06 

11.47 
11-65 
12-75 
12.36 

+  O.OI 
—  O.O2 
4-0.08 
+  0.08 

11.44 
ii  .69 
12-47 
12-35 

—  O.O2 
+  O.O2 
—  O.2O 
+  0.07 

ii  .46 
11.68 
12.78 
12.13 

o.oo 

+  O.OI 
-f  O.  II 

-0.15 

1  1  .46 
ii  .67 
12.67 
12.28 

11.71 
ii  .92 
12.92 
12.53 

±0.01 
±0.02 
±0.13 
±o.  10 

Mpan 

12.02 

12.27 

±0.06 

40-INCH. 

June  8.                  July  12.                Aug. 

30.                Sept.  13. 

Mean. 

Mag.      A  Mag.     Mag. 

A  Mag     Mag. 

A  Mag.     Mag.      A  Mag 

Mag.  H 

.  Mag.P 

A  Mag. 

f                                        10 

59 
74 
81 
52 

—  O.  1 

+  0.1 
+  O.C 

o.c 

5       10.64 

7       

—  0.  1C 

)      ii.  oo    +0.25 
11.40    —0.17 

)        1  1  .  8O          O  .  OO 

12.  61     —0.09 

10-74 
it-57 
11.80 
12.62 

10.99 
11.82 
12.05 
12.87 

±o.  17 
±0.17 
±0.05 
±0.05 

/  •  •  •     •  •  • 

n                                                                  II 

r  .  .  .     i  i  .  68    —  o  .  i  2      ii 
s  .  .  .     12.67     -0.15      12 

Mean  

>i       11.89 
K)       1  2  .  66 

+  O.OC 
+  O.Oi 

11.66 

ii  .91 

O.  II 

k               

IS.< 

>4 

21 

+  O.  It 
+  0.2( 

1^      15-37    -0.13 
)      14.77    —  0.18 
13.07    -0.07 
r      14.72    —0.03 
)      15.01    —  0.21 
14.8          
i      13.97    -0.29 
i4-9±       

«5-5o 
14-95 
13-14 
14-75 
15-22 
i4-8± 
14.26 

15    21 

15-75 
15.20 

13  39 
15.00 

'5-47 
i5-i± 
14-51 
15-46 

±0.14 
±0.17 
±0.08 

±O.  II 

±0.20 
±0.21 

P   .  .    14.87    -0.08      .  . 

22 

+  O.C 

-        15- 

>8 

ft.        .         14.62         —0.13 

* 

'4- 
I.S- 

)2 
»2 

-fo.i- 

+  O.2< 

TI...     14.12    -0.14      1439 

e  

+  0.13     14-54 
—     15-36 

+  0.2i 

±o.  15 

94 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


MAGNITUDE 
IS. IS 14-  13  .      /Z  II  10 


6IQO  RV  HCRCULIS 


30 


10 


i 


FIG.  19. — MAGNITUDE-CURVE  FOR  RV  HERCULIS. 


CHAPTER   VII. — RV   HERCULIS. 


95 


TABLE  58.—  6100  RV  HERCUUS.    VISUAL  OBSERVATIONS  OF  THE  VARIABLE. 


No. 

i 

2 

3 
4 
5 
6 

7 
8 

9 
10 
ii 

12 
'3 
14 
15 

16 

17 
18 

19 
20 

21 
22 

23 
24 
25 
26 

27 
28 

29 
30 

3' 
32 
33 
34 
35 
36 
37 
38 
39 
40 

4' 
42 
43 
44 
45 
46 
47 
48 

49 
5° 
51 
52 

Date. 

Ocular. 

£ 

3 

i 
I 

<! 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing 

t. 

A  Mag. 

Month 
and  Day. 

Hour 

:.S.T. 

Julian 
Day 
G.  M.  T. 

Steps. 

Mag. 

1897 
Aug.  23 

24 

27 
29 
3° 
Sept.    3 

7 

12 
17 
21 

22 

25 
28 

Oct.      i 
13 
M 

25 
29 
Nov.  ii 
16 
Dec.  29 
3' 

1898 
Jan.    18 
28 
Feb.    1  2 
'5 
24 
Mar.     2 

23 
Apr.      i 
ii 

15 
26 
May     7 
June  13 
'3 

21 
25 

July     6 

7 
July   21 

23 
Aug.     8 
18 

22 
24 
27 

Sept.    2 

7 
20 
Oct.      5 
ii 

9 
9 

9 

8 

9 

8 
8 
8 
7 

7 

7 
8 
8 
8 
7 
7 
6 
6 
6 
6 
6 
it 

18 
18 
18 

i? 
18 

17 
17 
16 

9 
16 

9 
9 

12 
12 
10 

13 
IO 
10 
IO 
IO 

9 

IO 

9 
9 

8 

7 
6 

2410000+ 
4160.63 

4161.63 

4164.63 
4166.58 
4167.63 
4171-58 
4I75-58 
4180.58 
4185.54 

4189.54 

4190.54 

4193-56 
4196.58 
4199.58 
4211.54 
4212.54 
4223  50 
4227.50 
4240.50 

4245  •  50 
4288.50 
4291.00 

4309.00 
4319.00 
4334-0° 
4336  96 
4345  •  98 
435I-96 
4372.96 
4381.92 
4391.63 
4395-92 
4406  63 
44I7-63 
4454 
4454 
4462.75 

4466.75 
4477-67 
4478.79 
4492.67 
4494-65 
4510.67 
4520.67 

4524-63 
4526.65 

4529-65 
4535-61 
4540 
4553  56 
4568.54 
4574-52 

80 

[150 
80 

!  so 
i  80 
I  so 
1  so 
150 
150 
so 
150 
150 
150 
150 

150 

150 
150 
150 
150 
15° 
150 
15° 
150 
150 
150 
15° 
150 

150 
150 
150 
150 
150 
150 
40 
4o 
150 
150 
15° 
150 

275 
so 

so 
so 
175 
15° 
150 
150 
150 
150 

So 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

6 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

12 

24 
12 
12 
12 
40 
8 
12 
12 
12 
12 
12 
6 
6 

6 
6 
6 
6 

uid  62—  31;  

40.8,  42.  i  

41.4 
40.4 

39-5 
38-5 
37-6 
37-3 
36-4 
33-8 
31.0 

28.7 

28.8 
27.0 
25.8 
25.6 
<36 

<24 
<26 

<25 
<27 
<26 

<44 

10.40 
10.57 

10-75 
10.90 
ii.  06 

II.  10 

11.25 
ii  .69 

12.  IO 
12.50 

12.49 
12.77 
12.96 
12.98 
<I2.3 
<I3-2 
<I2.9 

<i3-i 

<I2.8 
<I2.9 
<IO 

<I2.3 

13.01 
11.79 
10.97 
11.17 

II  .00 
10.73 
10.53 

II  .00 
11.70 
11.80 

12.  IO 

13.13 

<i4-i 

<i4-7 
i5± 
H-7± 
13-27 
14-97 
<i3-7 

I4-2± 

13.28 
11.82 
11.67 

poor 
good 

good 
good 
good 
moon 
moon 
fair 
fine 

good 

good 
good 
good 
good 
good 
good 
good 
good 
good 
fine 
low 
good 

fair 
good 
fair 
good 
good 
good 
good 
good 
fair 
good 
good 
fine 
good 
good 

fair 
moon 

good 
good 
good 
good 

fair 
good 
good 
good 
fair 
good 
good 

o 

i 

4 
6 

7 
ii 

15 

20 
25 
29 
30 

33 
36 
39 

149 
159 
'74 
176 
185 
191 

12 
21 
31 

35 

46 

57 
94 
94 
1  02 
106 

"7 
118 
132 
134 
150 
1  60 
164 

169 

'75 
1  80 

193 
8 

'4 

-0.13 

+  O.OI 

+  0.18 
+0.30 
+  0.46 

+0-43 
+  0.43 
+  0.88 
+  i.  19 

+  1-50 

+  1-47 
+  1.67 
+  1.78 

+  1.71 

—  0.28 
—  0.89 
—  0.40 

—  O.O2 
+  O.24 
+  O.  12 

—  o.  16 
+  0.18 
+0.66 
+  0.65 
+  0.65 
+  I-33 

+  o.8± 

+  o.3± 

+  0.50 

+  O.I± 

+  0.03 
-0.68 
-0.38 

-0.15 

+  0.06 
+  O.22 

+  o.  14 

—  0.06 
-0.03 

6311,  vi—  2d  

4'-6,  4'  -3  } 
40.6,  40.3,  38.2. 
38.7,41-6  I 

Vld,  1>2/,  /4O,  02^  

trw  bx  QIU  . 

U2S  st,  or,  r2m  

::::::::::::::::: 

j 

641),  dm,  V2f  

651)  d2TJ  1140  "V2J 

40.6,  38.8,  39.2..  . 
39-6,37-8,37.4-39-2 

37-8,  39.2,  35.9..  .  . 
37-8,  37.7,  36.4..  .  . 
35-8,  35.2,  36.4..  .  . 
33-2,  33.9,  34.3..  .  . 
3'-3,  30-4,  3I-3--  •  • 
27-3,  29.4,  29.3..) 
28.8  ) 

d2V,  T)2f,  772-30  

dxv,  vo-ij,  zrjo  

d$V,  \2T),  1130  

/4D,  ro-io,  T>4f>  

T2TJ,  033,  Tllp  

fr6i»,  041;,  PITJ  
{ill—  2s,  o2t,  limit  2  <^t 

p2v,  V2s,  limit  3—4  <  s.  .  . 

o6v,  p4V,  VS,  TJ2t  

si—  2v,  limit  v  

28.3,  29.3  
27.4,  26.3  27.3..  .  . 

S2V,  Vt  

25.  3,  26.0  

v  not  seen,  limit  u 

•v  not  seen,  limit  3  <  s  . 
v  not  seen,  limit  i  <C  s 

v  not  seen  limit  s 

i>  not  seen  limit  i  <i  s 

11  not  seen,  limit  b 

s2v  ?  limit  v  ?  .  .  .  . 

25-3 
33-' 
38.2 

37-o 
38.0 

39-7 
40.8 
38.0 
33-6 
33-° 

3'-' 
24.6 

<i8 

fl—211  VO,  Tl^S  

35-7,  33-4,  30-3-  •  - 

vij  

•vo-if,  ds-qv  
•vj,  b6v,  di-2v  
i>2/,  661;,  vi-2d  

37-7,  36.3  
37.2,38.6,38.3.--  . 
39.2,  38.6,  41.3..  .  . 

40.6,  40.8,  41  .  2.  .  .  . 
38.8,37.2,36.4,39.6 

32-4,  34-2,  34-3-  -  - 
32-4,30.3,  34-2,  35-3 
29.3,  29.3,  34,8.  .  . 
24.3,  25.0  

OITJ,  fsv,  vir  

OIV,  Tip,  /3V,  T12Y  
r^T),  T12S,  U\TJ  

syv,  tiv,  limit  v  
•v  not  seen,  limit  8—  10  <  s 
•v  not  seen,  limit  2"  <  s  .. 
•vk  

9-5 

v  seen  limit  2M  <  s  .  .  .  . 

23.8 

12.2 
<2I 

P2V,  f  3-4*!  

v  not  seen  limit  6  <  s  .  . 

12.5,  12.0  

"v  is  iiM  <  s 

23-8 
32-9 

34-o 

1120,  ryu,  J4V  
vSs  D2—y  ov  /5~  6v  

35-4,  30-3,  33-2-  .  . 
35-3,35-8,33.4,3i.7 

35-3,34.2,34-4,35.8 
35-2,36.3,35-8,36.4 

37-3,36.9,35.7,37.3 
38.1,  39.7,  41.3.  . 

39-i,  41-2,  41-8.  . 
39  6,  39-3,  4'.2.  .  . 

34-4 
35-9 
36.8 

39-7 
40.7 
40.0 

11.58 
11.32 
1  1.  20 
10.71 

10.55 
10.66 

di-2v,  1/3-40,  /o-iv,  TI^T  .  . 
66-71;,  V2-3J,  vi-2d    
65-6-11,  i>4/,  V2d    
651),  rfo-ir,  i>4/    

96 


RESEARCHES  IN   STELLAR   PHOTOMETRY. 


TABUJ  58. — 6100  RV  HBRCUUS.     VKUAI,  OBSBRVATIONS  OP  THB  VARIABLE. — Continued. 


No. 

Date. 

Ocular. 

Aperture. 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing 

t. 

JMag. 

Month 
and  Day. 

Hour 
C.S.T 

Julian 
Day 
G.  M.  T. 

Steps. 

Mag. 

53 
54 
55 
56 
57 
58 

59 
60 
61 
62 

63 

64 

65 
66 

67 
68 

69 
70 

7i 
72 
73 
74 
75 
76 
77 
78 
79 
80 
81 
82 

83 
84 

85 
86 

87 
88 
89 
90 

9' 
92 

93 
94 
95 
96 

97 
98 

99 

1898 
Oct.   15 

3i 
Nov.     5 
ii 

12 
19 

1899 

Jan.     8 
10 
Feb.   15 
Mar.     4 

19 
Apr.     4 
16 

21 

28 

May     i 
4 
9 

18 

29 
June    3 
13 
24 
July     8 
Oct.      7 
17 
24 
30 
Nov.     4 
IS 
20 

Nov.  26 

Dec.     5 
26 

1900 
Jan.     7 

20 
26 

Feb.     5 
18 

22 
25 

Mar.     7 
15 

22 

Apr.     4 

17 
18 

6 

7 
6 
8 

7 
6 

18 
18 

17 
17 
17 
16 

15 
15 
9 

9 
9 
9 

9 

9 
9 
9 
9 
9 
7 
7 
6 
6 
6 
6 

6 
6 

6 
18 

15 
15 
16 

15 
15 
18 

12 

15 
9 
9 

2410000+ 
4578.52 
4594-54 
4599-50 
4605  .  58 
4606.52 
4613-50 

4664.00 
4666.00 
4701  .  96 
4718.96 
4733-96 
4749.92 
4761.88 
4766.88 
4773-63 

4776.63  { 
4779-63  { 
4784-63  1 

4793-63  { 

4804.63 
4809  .  63 

4819-63 
4830.63 
4844.63 
4935-54 
4945  •  54 
4952.50 
4958.50 
4963  50 
4974-50 

4979-  50  { 
4985-50\ 

4994-  50  { 
5016.00 

5027 
5040.88 
5046.88 
5056.92 
5069  .  88 
5073-88 
5076.98 
5086 

5094 
5101.75 

5114-88  | 
5125.63 
5I26.63J 

80 
150 
150 
150 
150 
150 

150 
200 
150 
150 

40 
40 
40 
40 
40 
150 
40 
150 
40 
150 
40 
150 
150 
150 
150 
150 
200 
150 
80 
150 
150 
150 
150 
40 
150 
40 
150 
40 
150 
200 

200 

350 
35o 
350 
350 
350 
350 
275 
350 
350 
275 
275 
15° 
134 
275 

6 
6 
6 
6 
6 
6 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

6 
40 

4° 
40 
40 
40 
40 

12 
40 
40 
12 
12 
6 

12 
12 

d2v,  )2T>,  i>4r  
di—2Ti,  1130,  J2v,  iiqr  

37-8,  35-2,  37-3--- 
38.3,36.4,35.2,37.3 
32.2,32.3,  32.4,33.3 
30.9,  29.8  
29-9.  29-3  

36.7 
36.8 

32-5 
30-3 
29.6 
26.3 

<25 
<24 

29.6 
37-6 

44-5 
46.6 

45-9 
44-9 
44-0 

43-3 
42.6 
42.0 

37-4 

32-7 
30-6 

24-3 

<26 
<24 

36.3 

41  .0 

41.3 
41-7 

42.0 

40.9 
41-3 

40.1 

36.1 
25  ± 

<23 

II  .20 
ii  .  19 

11.88 

12.22 
12.35 
12.87 

<i3-o 

<I3    2 

12.35 

1  1.  06 
9.88 
9.66 
9-77 
9-84 
9-99 

IO.  IO 

10.23 

10.31 

11.05 
11.85 

12.  19 

I3-I6 
<I2.g 

<I3  * 

11.26 
10.48 
10.43 

10.37 
10.31 
10.50 

10-43 
10.62 

ii  .29 
13.0 

<J3-4 
I5± 
14.96 
15  09 

<I4-2 

15-45 
<«5  5 
<i3-5 
<i3-7 
14.41 

13-42 
12.49 
12.29 

good 
fair 
good 
fair 
fair 
moon 

poor 

18 
34 
39 
45 
46 
53 

4-0-42 
4-0-07 
4-0-62 
4-0.80 
+  0.90 
+  1.24 

/5ii,  nil,  0111,  v6s  .... 

02-37;,  TJ2-y  
03-471,  vis  

"v  glimpsed  limit  2  <  j 

v  not  seen,  limit  3-4  <  s.. 
r\Tj,  vo—is  
/2i»,  7147-,  7/40,  vo—  id  

29.3.  27-8  
35-2,  37-3,  37-4.  40-3 
45.1,  45.2,  43.3... 
45-6,  47-7  
45-2,  45-6,  47.3.  . 
44-7-  44-6,  45.8.  . 
44.2,  43.6,  44.8..  . 
42-6,  43-8  ) 
42-',  44-8  j 
42.6,  41  .8  ...    .    ) 

good 
fair 
good 
good 
good 
good 
good 

good 
fair 
fair 

fair 

good 
good 
good 
fair 
good 
fair 
fair 
fair 
fair 
good 
fair 

fair 
good 

fair 
fair 

good 
fair 
good 
good 
poor 
fair 
poor 
good 
moon 
good 

good 
poor 
good 

141 

158 
173 
189 
i 
6 
13 
16 

19 
24 

33 

44 
49 
59 
70 

'75 
185 
192 
198 
3 
14 

19 
25 

34 
56 

80 
86 
96 

"3 

141 

'54 
165 
1  66 

-1-37 
-i.59 
-i-54 
-0.99 
-0.78 

-0.75 
-0.71 

—  0.64 
—  o.  56 
-0.58 

—  0.06 

4-0.46 
-fo.66 
+  1.63 

+  O.O2 
-0.30 

—  o.  16 
-0.15 
—  0.26 

—  O.2I 

-0-37 
—  O.29 

+  0.71 
+  1.23 

+  i'?3 
+  i  .20 

+  0.99 

+  0.68 
+  0.44 
+  0.40 
+  0.30 

7116,  e6v,  713—  4<i  
7116,  63-411  
e6v,  vib,  vj-8d  
e6-7T>,  -vb,  v6d  
ed-8v,  biv,  v$d  

6211,  T>4d  

62-311,  Ti$d  

0211  V2d 

0211,  113-4^  
byv,  7>2—  3rf  

42-6,  43-3  ) 
41-6,  42-3  ) 
42.1,  4.2.1   j 
37-6,  37-8  > 
37-3,  37-2,  37-3--) 
33-7,33-3,32-4,  31-3 
30.8,  30.3  

62-311,  712-3<i  
66-811,  d2T>  

6(2-311,  7i/,  H4r.  
/3~  411,  w,  0111,  114  s  ...  . 

f2-31l,  113*  

J-3H  . 

11  not  seen,  limit  1—2  <C  j 

11  not  seen,  limit  3-4  <  s... 
Tj2r,  /2n,  1/2—30,  din  

35-3.  35-2,  35-9,  38-8 
41  .8,  40.7,  40.6..  .  . 
41.2,  38.6,  42.8.  .. 
41  .1,  41.2,  42.8.  .. 
4'-6,  43-3,  4'-2.  .. 

4O.6,  41  .2  
4O.6,  41.8  1 
40.6,  42.3  { 
39.6,  40.8,   39.2..) 
38.6,  41.8,  40.7..) 

35-8,  34-9  ) 
38-3,  35-4  i 

7i2d,  U3-4/,  6411  
H4/,  66i>±,  v$d  
63-411,  T/4/,  irjd  
biv,  -V3-4d,  n4/  
6411,  D4/  
6411,  V2d.  

6411,  H2-3<£  
6511,  Tlld,  1>2/  

6611,  T/2d,  113—  4/  
^471,  ni—  20  

dl-27i,  K20  
J27J  ?  

11  not  seen  limit  4  <  j 

11  glimpsed  not  <  I5M 

P211  711*  713&  1*20 

12.5,  12-4,  II-5,  12-0 

10.  i,  n-4,  n-5,  ii'O 

12.  I 
II  .  I 

£411  11*  "v^k  T)  i  ft 

•v  not  seen,  limit  iiM  <  s.. 
P6v,  tya,  vo-ik  
11  not  held,&  and*  glimpsed 
11  not  seen  limit  4  5  <  « 

8.5,  8.4,  9.0  

8.6 

<   8.5 

<22.4 

H4/"1  17211  «8—  1011  ii5/>  .... 

18.5,  13-7,  (i7-9),  19-5 
26.9,  23.8,  17.4..  I 

'5-9 
22.7 
28.8 
30.0 

7!«,  .£3-411,  V21  

•V2S,  H4«,  ri—  211  
in  j^-  

29  3,  30-9,  3i  -8-  •  \ 
28.3  / 

CHAPTER   VII. — RV   HERCUUS. 


97 


TABLE  58. — 6100  RV  HERCULIS.    VISUAL  OBSERVATIONS  OP  THE  VARIABLE. — Continued 


No. 

Date. 

ti 

1 

1 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing. 

'• 

A  Mag. 

Month 
and  Day 

Hour 
C.  S.  T. 

Julian 
Day 
G.  M.  T 

Steps. 

Mag. 

IOO 
101 

1  02 

103 

104 

105 

106 
107 

108 

109 
no 
in 

112 

"3 
114 

"5 
116 

ii? 
118 

119 
1  2O 
121 
122 
123 

124 

125 
126 
127 
128 

129 
130 
131 
132 
133 
134 

135 
136 
'37 
138 

139 
140 
141 
142 

143 
144 

'45 
146 

1900 
Apr.  30 
May   19 

June  17 
July   12 

21 

Aug.  30 
Sept.  12 

13 

Oct.     4 
16 
26 

1901 
May   1  8 
June     3 

July   20 
Oct.    1  8 

31 
Nov.    7 

12 

1902 
Feb.    3 
Mar.    5 
28 
July  27 
Oct.     i 

1903 
Mar.  20 
Apr.     4 
May  17 
July  24 
Sept.  20 

1904 
May  14 
June  19 
July     i 

3' 
Aug.    4 
u 
Sept.    2 

'4 
Oct.      8 
Nov.  30 

1905 
Jan.    12 
Feb.   14 
Mar.     5 

12 
26 

Apr.     4 
u 
Apr.   22 

IO 

9 

'3 
9 

IO 

9 
9 
9 

8 

8 
9 

7 

9 

10 

8 

7 
8 

7 

u 
16 

8 

17 
15 

IO 

IO 
IO 

9 
6 

18 
16 
16 
'3 
13 
15 
16 

IO 

2410000  + 
5140.67 
5159-63 
5I7I-79 
5188-63 

5213-69 

5222.63 
5262.63 
5275-63 

5276.58 

5309-63 
53I9-54 

5523-63 
5539  67 

5586 

5676.58 
5689.54 
5696-58 

5701-54 

5784.96 
5814-71 

5858' 
6024.58 

6194.96 
6209  .  88 
6252 
6320 
6378 

6615 
6651 
6662.67 

6693- 
6697.67 
6704.67 
6726 
6738 
6762.61 
6815.50 

6859.00 
6891.92 
6910.88 
6917.77 
6931  •  79 
6940  .  88 
6947.92 
6958.67 

150 
'SO 
237 
150 

237 

150 
350 

75 

237 

237 
450 
ISO 

80 
237 

80 

6 
6 
40 
6 

40 

6 

40 

12 
40 

40 
40 

6 

12 
40 

24 

12 

/it1,  TIO,  i>4r,  v6s  

JO-ITI,  T120  
flV,  T12T,  T>6s,  VO   

/4^,  112—  3r    TJ20      .      . 

36.2,33.4,37.3,33.3 

36.7,  35-3  
36.2,  35.3,33.3,  33-4 

33-2,  35-8,  35-  4-  •  •  • 
i 

35-o 
36.0 

34-5 
34-8 

24-3 
'3-4 

11.49 
u  .30 
11.38 
11.51 

12.26 

I3-I7 
14-77 

good 
fair 
good 

fair 

fair 
good 

i  So 
199 
1  1 

28 

53 
62 
1  02 

+0.50 
+0.77 
+  0.71 
+  0-53 
+  0.63 

+  1.19 
+  0.57 

+0.48 

i?3*p,  up,  viP  7746 

12.7,  10.0,  15.5,  15.4 

•v  not  seen,  limit  I  <«.... 

u  .0.  .  .  .  ) 

II  .2 

14.96 

good 

116 

(P  2—  yil,  Tli,  V2~3k,  151),  Tllf. 

12.0,11.4,  11.0,  10.7) 

s6vt  ^5-61,  03-41;    

21.3,  21.2,  23.4..  .  . 
26.3,  28.4  

21.9 
27-3 

22.3 
31-8 

<26.9 

<24-4 
10.8 

41.4 

35  ± 
33-3 

13-53 
12.71 

'3-47 

12.00 
<I2.8 

15.13 

10.40 
11.48 
11.77 

ii.  9± 
10.51 

10.22 
10.96 
<n.8 
13  98 
10.71 

10.69 
12.31 
12-55 
<t3-7 
<i3.oo 

<i3-4 
13-2 

fair 
fair 

good 
fair 

fair 

137 
149 

163 
'79 

-0.38 
-0-57 

+  1.23 
+  0-57 

s^v  v  near  limit  

(*,  «,  y,  and  ft  near  limit  .  \ 
i  P  and  *  seen,  but  not  k  ,  \ 
u  not  seen   limit  * 

3'-3,  32.3  

limit  of  24-inch  i5M.2 

60 

350 

80 
237 
237 

237 

237 
40 

67 
350 
40 

40 

60 
40 
67 
67 
67 

237 

40 

40 
250 
237 
237 
237 
237 
237 
237 

24 
40 

12 
40 
40 
24 
40 

40 

6 

12 

40 

6 

6 
24 
24 
6 

12 
12 
12 
24 
40 

6 

6 
40 
40 
40 
40 
40 
40 
40 

v  not  seen,  limit  2-3  <  *.  . 
»>5V,  viP,  Pyv,  vik,  div..  .  -j 

10.7,11.0,11.5,10.4} 

10.  5  ) 

fair 

fair 
good 
poor 

fair 
good 
poor 
poor 
good 

good 
good 
good 
fine 
fair 
good 
good 

141 

24 
54 

77 

64 

34 
49 

160 
18 

55 
1  02 

'37 
166 

+  1.41 
-0.49 

—  0.20 
-0-93 

—  0.89 
-0-57 

+  1-49 
—  0.07 

—  1.02 
—  I.OI 

-1.65 

—  O.9I 

+  I.2± 

40.  i,  42  8  .  . 

v  is  between  /  and  r      .    . 

photograph 

42.7 

V  not  seen,  limit  o      

<33 
19.0 

j6—  8v,  vzn  
photometer  .    . 

20.3,  17.7  

b6v,  vd,  v$f  

38.6,  39.8,  42.2..  .. 
30.4,  30.3,  28.8..  .  . 
24-8,  31  9  

39  9 
29.8 
28.4 

S2-3V,  t>5«  
T>  not  seen  limit  i**  <  s   .. 

v  not  held,  perhaps  a  i—  2V. 
v  not  seen  limit  4  <C  a 

<25-4 

<23 

23  9 

v  perhaps  glimpsed,  «3f  ?  . 

18.3  

r2f,  vjs  

06-8V,  V20.  
>>4-5T,  T>P,  «LOD±  

sio-12-v,  Tin,  v6l  

S^T),  v6«  

40.6,  41  .8  

3'-3.  34-3  
19.9,  20.7  
26.4,  28.9  
24-3.  32-9  

II.  2,  14.5,  (16.9).. 

13-7,  '9-5  
16-3,  23.3,  21.7.... 
23-3,  29.3  

41.2 

32.0 
20.3 
28.1 
26.5 
13-4 

22.9 
26.3 

10.47 

u  -95 
13-77 
12.58 
12.82 
14.76 

13-40 

12.88 

fair 

fair 
good 
fair 
good 
fair 

good 
fair 

55 

99 

«5i 
157 
171 
1  80 
187 
198 

-1.24 

-2.08 
-0.30 

—  0.61 

+  O.  IO 

+  2.36 

+  3-45 
+  2.65 

+  2.33 

98 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABLE  58. — 6100  RV  HERCULIS.    VISUAL  OBSERVATIONS  OF  THE  VARIABLE. — Continued. 


No. 

'47 
148 
149 
150 
151 
152 
153 
154 
155 
156 
'57 
158 
159 

Date. 

1 
u 

O 

Aperture. 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing. 

/. 

4  Mag. 

Month 
and  Day. 

Hour 
C.S.T. 

Julian 
Day 
G.  M.   T. 

Steps. 

Mag. 

1905 
Apr.  30 
May    31 
June   13 

22 

July  24 
Aug.     9 
20 

->*> 

Sept.    2 
19 
Oct.    21 

3« 
Nov.   1  8 

13 
9 
14 
9 
9 
8 

9 
9 

12 
II 

8 

7 
6 

24100004- 
6966  .  79 
6997.63 
7010  83 
7019  .63 
7051-63 
7067.60 
7068.62 
7080.63 

7091.75 
7  108  .  7  i 
7140.58 

7150.54 
7168.48 

237 
40 

237 
150 
150 
150 
237 
237 
237 

2J7 

237 
237 

237 

40 
6 
40 
6 
6 
6 
40 
40 
40 
40 
40 
40 
40 

7)1—  2  S  

28.8 
44.8 

12.48 
9-85 

IO.OO 

9.79 

10.90 
12.92 

13.11 

13-  19 

13.96 

14  95 
J4-75 
13.89 
12.80 

good 
good 
good 
fair 
fair 
moon 
poor 
good 
fair 
fair 
good 
good 
good 

6 
37 
50 
59 
9i 
107 
118 

120 

'3> 
148 
1  80 
190 

8 

4-1.98 

-1.35 
-i.6± 

—  2.12 
-2.70 

-i-39 

-'•31 
-1.33 
—  o.  14 

4-2.15 
+  3.76 
4-3.21 

4-2.20 

eSv,  Tib,  vjd  
photometer  

43.2,  44.6,  46.8  

•v$b,  v$d,  e8v  

d2TI,  Tllf  
SI—  27>i 

47.6,  43.8,  43.2..  .  . 
37-8.  39-2  

45-2 
38.5 
25.8 
24.6 
24.1 
19.0 

12.  I 

13  6 
19-5 
26.8 

J5"-  "3-4"  
.53-411,  vi"  
«5*>,  u4>>  

22.3,  26.8  
23-8,  24.3  
18.3,  '9-7  

147),  ill  P  

a3V,  T})  V»P±  
SIV,  VJ  a  

11.7,  15.5  
20.3,  18.7,  (22.5;.. 
26.3,  30.3  

CHAPTER   VIZ. — RV   HERCUUS. 


99 


§ 


X 


I 


§ 


S?          5          59          53  5 

FIG    20. — LIGHT-CURVE  OF  RV  HERCUUS. 


IOO 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABI.E  59. — 6100  RV  HERCULIS.     MEAN  MAGNITUDES  FROM  i6J  DAY  GROUPS. 


Group 
T.  D.. 

No.  ... 

i 

16 

2 
•j-l 

3 
5° 

4 
66 

5 

8-1 

6 

IOO 

7 
116 

8 
133 

9 

I  SO 

IO 

1  66 

it 

181 

12 
2OO 

(t 

6 

26 

36 

I4.O 

I  ^O 

I  7S 

188 

M 

10.86 

12  .  2O 

12.90 

T  l  .  OI 

1  1  .  7O 

1  1  .  07 

10  86 

4160  ' 

JM 

-4-O    37 

+  1     26 

4-  I     72 

—  o  28 

—  o  89 

+  o  18 

No 

7 

4. 

•i 

2 

2 

4360  - 

f 

M 

JM 
No. 

r       / 

12 

10-53 

—  o.  16 
i 

1  1 

26 

n-35 
+  0.42 

2 

18 

40 

1  1.  95 
-1-0.65 

2 
41 

57 
13-13 
+  I-33 

i 

c^ 

104 

14.85 
+  0.55 

2 

118 
14-97 
+0-50 
I 

'34 

I4-2± 

+  0.1± 

I 

•58 

12.  26 

-o-34 
3 

is8 

175 

11-37 
+  0.04 
3 

17-3 

'93 
IO.7I 

—  o.  14 

I 

1  80 

M 

10  60 

1  1   20 

II     OI 

12    87 

12     ^S 

1  1  06 

9  88 

9  66 

4560  < 

ATA 

o  04 

-f-o  42 

-f-o  60 

4-  i  ,  24. 

—  I     ^7 

—  I     SQ 

—  I     S4. 

—  O   QO 

No. 

2 

I 

4 

I 

I 

I 

I 

I 

If 

9 

22 

42 

4O 

175 

192 

M 

9Q2 

10  27 

II    7O 

II    26 

IO    4."? 

4760  < 

JM 

O    72 

—  O    S4. 

4-O    ^5 

-\-i    6* 

-f-O   O2 

—  O    2O 

No. 

4 

2 

•2 

I 

I 

•z 

4960  i 

< 
M 

JM 

No. 

\       t 

8 
10.40 
-0.24 

2 

II 
11.38 

22 
10.52 

-0-33 

2 

28 
11.51 

34 
ii  .29 
+O.I7 
i 

58 

12-  72 

56 
i3-0± 

+  I-2± 
I 

80 

15.  o± 

—  2.IO 
t 

9i 

J5-°4 
+  1.46 

2 

"3 

15-45 
+  0.99 
i 

109 

14.92 

141 

14.41 

+  0.68 

i 

'37 
13.53 

162 

12-73 
+  0.38 

3 

149 
12.71 

180 
11.49 
+  0.50 
i 

199 

11.30 
+0.77 
i 

5160  < 

JM 

+o  71 

+  O    SI 

-f-o  91 

—  O.  SQ 

—  o  ^8 

-0.57 

No. 

I 

I 

2 

•i 

i 

i 

[t 

161 

170 

M 

1^-47 

12.  OO 

536°  < 

JM 

+  1-23 

+  O-97 

No. 

i 

I 

r     t 

M 

T  r     17 

556o  < 

4M 

4-  1    4.1 

No 

/ 

M 

1  1    48 

576o  < 

JM 

L     No. 

!t 

64 

M 

596o  < 

JM 

T      CX 

No 

< 

4.2 

160 

M 

i  -5.98 

6160  • 

JM 

—  O    77 

+  1.49 

No. 

2 

i 

j 

< 

18 

M 

6360^ 

JM 

1 

No 

CHAPTER   Vll. — RV   HERCUUS. 


lot 


TABLE  59.— 6100  RV  HERCUUS.     MKAN  MAGNITUDES  FROM  i6§  DAY  GROUPS.— Continued. 


Group  No  .... 
J.D  

i 
16 

•2 

33 

3 
5° 

4 
66 

5 
83 

6 
IOO 

7 
116 

8 
133 

9 
150 

10 

166 

ii 

183 

12 
2OO 

c        t 

55 

91 

102 

137 

166 

M 

10.69 

12.31 

12  55 

13.00 

I3-2± 

656°  1      JM 

—  i  .02 

—  1  .01 

-1.65 

—  0.91 

+  I.2± 

L  No 

i 

I 

i 

i 

I 

r          t 

55 

99 

131 

151 

M 

10.47 

ii  95 

13-77 

12.58 

6?6°  i      JM 
(_     No 

-1.24 
i 

-2.08 

i 

—  0.30 

i 

—  0.61 
i 

(          t 

6960          JM 

[^      No. 

r   M< 

Means  {      m 
I     No. 

9 
10.62 
—0.03 

i? 

23 
1  1.  02 

+  0.15 
14 

4? 
11.87 
+  0.52 
i? 

55 
ii  .91 

+  0.32 

7 

78 
i3-5± 
-0.58 

2 

94 
13.  10 

—  O.2I 

4 

107 
14.44 

+  0    12 

6 

124 
'4-37 
+  O.  IO 

2 

140 

13-77 
-0.27 

7 

158 
12.64 
-0.08 
14 

176 
ii.  18 
—0.04 
9 

192 

10.59 

—  O.02 

8 

10 


DAYS 

too 


5 


14- 


15 


6100  RV  HERCVUS 


Max.* 
Min.  '< 
M-m- 


•Zoo 


Fio.  si.— MEAN  LIGHT-CURVE  OF  RV  HERCUUS. 


102 


RESEARCHES   IN   STELLAR    PHOTOMETRY. 


TABLE  60. — -6100  RV  HERCUUS.     OBSERVED  MAXIMA  AND  MINIMA. 

Elements  of  maximum.     1898,  March  12  (J-  D.  2414361)  +  200^  E.     M  —  m  =  81<J. 


MAXIMA. 

MINIMA. 

i 

w 

Date. 

Mag. 

Corr. 

Wt. 

1 

W 

Date. 

Mag. 

Corr. 

Wt. 

Calendar. 

J.  D 

H. 

P. 

Calendar. 

J-  D- 

H. 

P. 

—  I 
o 

i 

2 

3 
4 
5 
6 

7 
9 
10 
ii 

12 

13 

1897  Aug.  23 
1898  Mar.  15 
Sept.  28 
1  899  Apr.     6 
Nov.     i 
1  900  May   21 
Dec.     6 
1901  June  29 
1902  Jan.   22 
1903  Feb.  24 
Sept.  22 
1904  Apr.     2 
Oct.   1  8 
1  905  June  14 

4160 

4364 
456i 
475i 
4960 
5161 
536° 
5565 
5772 
6170 
6380 
6572 
6772 
7011 

me 

to-75 
10.8 

9  93 
10.50 

11-55 
me 
me 
me 
me 
me 
me 
me 
9  95 

—    i 

+   3 

0 

—  10 
—    i 

0 

+   4 
+  11 

+   9 
+  19 

+  11 
+  u 
+  50 

10 

12 
2O 

17 
12 
12 
I 

I 
2 
2 

I 
I 

3 
15 

0 

i 

2 

3 
4 
5 
6 

7 
8 

9 
10 

12 
13 
14 

1897  Dec.     i 
1  898  July    2 
1  899  Jan.  15 
Aug.  ii 
1900  Feb.  17 
Sept.  1  1 
1901  Mar.  26 
Oct.  29 
1902  May  20 
Dec.  16 
1  903  July  14 
1  904  Aug.    3 
1  905  Mar.  15 
Oct.    4 

4260 

4473 
4670 
4878 
5068 

5274 
5470 
5687 
5890 
6100 
6310 
6696 
6880 
7"3 

me 
15-6 
me 
me 
15.60 
15.22 
me 
me 
me 
me 
me 
14.2 
15-25 
15-65 

—  20 

-   7 
—  10 

—  12 

-   6 

—  IO 

+   7 

+  10 

+  20 

+30 

+  16 
+  40 
+  43 

i 
8 
i 
i 

12 

8 
i 

2 
O 
O 
I 
2 

9 

12 

10.50 
10.6 
9.68 
10.25 
11.30 

'5-3 

15-35 
14-97 

14.0 
15.00 
15  40 

9.70 

The  mean  light-curve  was  derived  from  the  observations  up  to  1905  March 
:5  (J.  D.  6911).     So  far  the  period  200  days  satisfied  the  measures,  but  the  suc- 
'  ceeding  observations,  covering  the  maximum  and  minimum  of  epoch  12,  indicate 
'.  a  slightly  longer  period,  perhaps  204  days.     The  light-curve  has  several  notable 
features.     The  range  is  more  than  five  magnitudes,  unusually  large  for  the  length 
of  period.     The  decline  is  as  rapid  as  the  rise,  and  the  minimum  is  as  sharply 
defined  as  the  maximum.     There  is  a  suspicion  of  a  secondary  maximum  arising 
from   three    anomalous  observations    near  the   minima  of   epochs    ii  and   12, 
but  the  evidence  is  hardly  sufficient  to  definitely  settle  the  question.     A  consider- 
able range  will  be  noticed  in  the  magnitude  at  the  maxima,  the  star  reaching 
9.7  at  epochs  2  and  12,  but  only  reaching  11.3  at  epoch  4. 


CHAPTER  VIII. 


6894  S 
R.  A.  igh  gm  6»-3;  Dec.  +  25°  50'  17"  (1900). 

This  star  was  numbered  868  by  Espin,  who  noted  a  decline  from  gth  to  i2th 
magnitude  in  1893.  The  variability  was  confirmed  by  H.  M.  Parkhurst,  and 
the  notation  was  assigned  by  Chandler  in  Astronomical  Journal  14,  in.  The 
notation  is  confused  in  the  Nachrichten,  where  this  star  is  numbered  6895,  while 
the  number  6894  is  given  to  X  Lyrae,  about  i°  north  of  S. 

Observations  began  in  October,  1896;  the  places  of  the  variable  and  the 
brighter  comparison  stars  were  measured  with  the  6-inch  in  that  month,  the 
places  of  the  faint  stars  s,  x,  and  those  with  Greek  letters,  were  measured  with 
the  4O-inch  in  June,  1900.  The  stars  e,  c,  and  E'  are  in  the  Cambridge  (Eng.) 
A.  G.  Catalogue.  Using  the  coordinates  in  Table  63,  the  position  of  the  variable 
relative  to  these  stars  results  as  given  at  the  head  of  the  page,  with  a  probable 
error  of  ±o?.2  and  ±o".5. 

The  photometric  measures  of  the  brighter  comparison  stars  are  a  little  above 
the  average  in  accordance,  the  fainter  stars  a  trifle  below  the  average.  The  faint 
star  j9  has  a  very  discordant  measure  with  the  4o-inch  on  1904  May  20,  in  good 
seeing.  The  suspicion  of  variability  aroused  seems  to  be  confirmed  by  the  photo- 
graphs, but  not  by  the  other  visual  comparisons.  It  is  therefore  reserved  for 
further  investigation. 

The  photographic  chart  is  given  on  a  larger  scale  than  usual  in  order  to  show 
clearly  the  close  comparison  stars  a  and  /J. 

TABLB  61. — 6894  S  1/VR.s.    STANDARD  MAGNITUDE  STARS. 


Star. 

B.  D.  No. 

1900. 

Color 
P.  DM. 

Magnitude. 

Residuals. 

R.  A. 

Dec. 

Catalogue. 

Measured. 

From  Cats. 

3 
Nights 
inter 
se. 

H.  C.  0. 

P.  DM. 

H. 

P. 

H. 

P. 

£" 
G' 
H' 

0 

+  25  3757 
+  26  3477 
+  24  3687 

Mean  . 

h    m     s 
19  09  47 
19  07  40 
19  10  ii 

Q                 I 

+  25  35-1 
+  26  04.9 
+  24  50.6 

GW 
GW 
W 

6.88 
7.40 
7.16 

7-24 

7-97 
7-50 

6.91 

7-45 
7.10 

7-33 
7.87 

7.52 

+  3 
+  5 
-6 

+   9 
—  10 

+     2 

±3 

±2 

±3 

7-15 

7-57 

7-15 

7-57 

±5 

±   7 

±3 

103 


IO4 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 
TABLE  62. — COMPARISON  STARS  IN  B.  D.  CATALOGUE. 


B.  D. 

1855- 

B.  D. 

i855. 

No. 

Mag. 

R.  A. 

Dec. 

No. 

Mag. 

R.  A. 

Dec. 

O 

km   s 

•        / 

0 

h  m  s 

O      / 

e 

+  25  3748 

8.8 

19  6  27 

+  25  3°-4 

b 

+  25  3752 

9-5 

19  7  02 

+  25  5i-9 

a 

+  25  3750 

9-5 

19  6  41 

+  25  45-2 

c 

+  25  3755 

8.9 

19  7  44 

+  25  58.1 

TABLE  63. — COMPARISON  STARS  FOR  S  LYR«  (!N  ORDER  OF  RIGHT  ASCENSION). 


Star. 

Coordinates  from  Variable. 

Light 
Scale, 
Steps. 

Magnitude. 

R.  A. 

Dec. 

Measured 

From  Curve. 

H. 

P. 

H. 

P. 

ft 

s 

* 

e 

-637 

-47.1 

—  922 

44-2 

8.40 

8.82 

k 

—  604 

-44.6 

+  113 

24.6 

11.18 

ii  .60 

r 

-574 

-42.4 

-602 

29.6 

10.50 

10.92 

I 

-553 

-40.9 

-   28 

24.6 

ii  .  18 

11.60 

a 

-465 

-34-4 

-   35 

34-2 

9.69 

IO.  II 

9 

-371 

-27.4 

-525 

29.6 

10.50 

10.92 

h 

-326 

-24.1 

+  344 

25.6 

11.05 

11.47 

i 

-318 

-23-5 

+  463 

32.6 

10.  06 

10.48 

TV 

-281 

-20.8 

-"5 

23-5 

H-34 

ii  .76 

U 

-281 

—  20.8 

+    H 

24-5 

II  .21 

ii  .63 

t 

-241 

-17.8 

+   47 

21  .O 

II  .67 

12.09 

b 

-192 

-14.2 

+  360 

34-3 

9.86 

10.23 

• 

—     22 

-    J-5 

+    13 

23 

14.01 

H-43 

ft 

-     9 

-  o-l 

+     8 

o 

var.? 

X 

+   43 

+   3.2 

+      12 

11.4 

12.82 

13-24 

X 

+   64 

+   4-7 

+   94 

18.4 

12.  18 

12.60 

A 

+   66 

+   4-9 

-    80 

I 

+  67 

+   5-0 

-399 

30.6 

10.46 

10.88 

B 

—  117 

+   8.6 

-   46 

s 

-137 

+  IO.  I 

+  173 

21.  0 

11.56 

11.98 

P 

+  170 

+  12.6 

-476 

27.6 

10.78 

ii  .20 

0 

+  178 

+  13.2 

-177 

24.7 

II.I8 

ii  .60 

D 

+  252 

+  18.6 

—      i 

21.5 

ii  .46 

11.88 

n 

+  322 

+  23.8 

-   86 

24.7 

II.I8 

ii  .60 

m 

+  346 

+  25.6 

+    58 

25.6 

10.90 

11.32 

c 

+  369 

+  27.3 

+  739 

42.2 

8.68 

9.  10 

d 

+  463 

+  34-2 

-837 

E' 

+  555 

+  41  .0 

-903 

6.91 

7-33 

STELLAR  PHOTOMETRY. 
+  30" 


N 


PLATE   8. 


-3<>s 


+  5' 


-5'— 


. 


+10' 


\       • 


•  • 


— +5 


m         • 


'  ' 


'A 
f 


•w 


a. 


_  r 

5 


•  ' 

P 


Scale,  i  mm  =7*.  8.  os 


S  —303 

6894  S  LYR^. 

R.  A.  1911.9111  [68.3.      Dec.+  25°  50'  17",  1900. 


bsr  i. 


CHAPTER   VIII. — S 


105 


TABLE  64. — 6894  S  LYRJB.     PHOTOMETER  MEASURES  OP  COMPARISON  STARS 


1903  November  7.                                            6  -INCH.                                                              Good. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

c. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

h     m 
21   17 

21   37 

• 

33 
36 

TJt 

11  ai 

£'0, 

G  at 

G' 
a 
b 
& 

I 
a 
G 

G  a  i 

F/ot 

H'ai 
H'a, 

15-5  15-0  15  5 
13.2  13.8  13.4 
18.7  19.0  18.9 

12.2    12.3    12.7 

31-3    31-6    31-9 
33.0   32.8    33.0 

37-9  37-2  37-2 
36.8  37.1  37.4 
33-9  33-3  33  2 
32.5  32.4  32.4 
12.3  12.4  12.8 
17.8  18.8  18.7 

IO.  I    IO.I       9.8 

13.9  14.4  14.2 
15.9  15.6  15.6 

15-33 
13-50 
18.87 
12.40 
31  -60 
32-93 
37-43 
37-10 
33-47 
32-43 
12.50 

18.43 

IO.OO 

14.17 
15.70 

15-52 
13-84 
18.65 

12.45 
32.02 
33-20 

37-27 

i  .02 

0.76 
1.44 
0.56 
2.94 
3-07 
3-59 

7.87 
7.61 
8.29 
7-41 
9-79 
9-92 
10.44 

8  29 
8.03 
8.71 
7-83 

IO.2I 
10-34 

10.86 

1903  November  8.                                                                                                                          Good. 

21     12 
21    38 

31 

34 

1 
6 
a 
F'a 
G'o 
£'o 
H'a 
H'a 
E'a 
G'a 
a 
b 
1 

36.  J  36.1  36.3 

33  o  33.7  33.7 
31.2  31.6  31.6 
6.0    6.1     5.7 
17.8  18.3  18.6 
15.0  14.9  15  o 
15.4  15.2  16.2 
16.0  15.2   15.3 
14.7   15.0  14.8 
18.8   18.3  18.6 
31.2  31.0  31.3 
33.1   32.6  32.9 
37-i  37  i   37  3 

36-17 

33-47 
31-47 
5-93 
18.23 

14-97 
15  60 
I5-50 
14-83 

18.57 
3I-I7 
32-87 
37-«7 

36-67 
33-17 
31-32 

3-53 
3-07 
2.84 
0.03 
i  .40 
0.92 

1.  01 

10.32 
9.86 

9-63 
6.82 
8.19 

7-71 
7.80 

10.74 
10.28 
10.05 

7-24 
8.61 

8.13 

8.22 

18.40 
14.90 
15.55 

i 

1903  November  24.                                                                              Seeing  good;  moon  6  days  old. 

23     4 
23  28 

51 

55 

G' 

a 
6 

( 

E'ai 
H'a, 
H' 
E'ai 

g 
b 
a 
G' 
G'a, 

12.3    II-7    12.  I 
31.0   3I.I    31.2 
3I.I    31.8    32.0 

37-2  37-4  37-3 
14.2   14.0  14.7 
15.8  16.  i   16.1 
9.7   10.9     9.9 
15.1   14.8  14.2 
38.1   37.8  37.9 

34-i   33-8  33-9 
33.1  32.2  32.4 
14.2   13.7   13-9 
19.8  20.  i    19.4 

12.03 
31.10 
31  63 
37-30 
H  30 
16.00 
10.  17 
14-70 
37  93 
33-93 
32-57 
13-93 
19.70 

12.98 

31-84 
32.78 
37.62 
14-50 

0.63 
2.91 
3.08 
3.62 
0.86 
i.  08 
0.30 

7-43 
9-7i 
9.88 
10.42 
7.66 
7.88 
7.10 

7-85 
10.13 
10.30 
IO.84 
8.08 
8.30 
7.52 

io6 


RESEARCHES   IN  STELLAR   PHOTOMETRY. 


TABLE  64. — 6894  S  LYR^E.     PHOTOMETER  MEASURES  OP  COMPARISON  STARS.- — Continued. 


1902  July  7.                                                         12-INCH.                                                           Very  good. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings 

C. 

Magnitude. 

i 
Mean  of  3 

Mean  of  6 

H. 

P. 

h    in 
16  30 

17  25 

O 

A' 

B' 

B     (12 

c 

E'a, 
a 
b 

g 
s 
m 
s 

g 
b 
a 
£'„ 
C' 
B'a* 
A' 

'4-7   13-4  13-3 
10.0     7.8     8.5 
24.5  26.2  25.7 
16.8   18.0  18.3 
16.2   17.9   17.6 

26.9  28.8  28.5 
30.5  31.0  30.0 
33.8  32.4  33.0 

44-0  45-3  46-2 
39-o  39.8  39.2 
42.2  43.7  44.4 

33-2  34-7  33-8 
27.2  28.9  27.9 
28.0  26.2  26.4 

II.  2     14.7     13.9 

16.2   17.5   17.5 

19.5    20.0    19.9 
II.  2    II.  O    II.  2 

13.80 
8.77 
25-47 
17.70 

17-23 
28.07 
30-50 
33-07 
45-17 
39  33 
43-43 
33  -  90 
28.00 
26.87 
13-27 
17.07 
19.80 
11.13 

12.47 

0.72 
0.32 

2.OI 

1-37 
I.  08 
2.41 
2.58 
3.02 
4-25 
3.69 

8.05 
7.65 
9  34 
8.70 
8.41 

9-74 
9.91 

10.35 
11.58 
II  .02 

8.47 
8.07 
9.76 
9.12 

8.83 

io.  16 
10.33 
10.77 

12.  OO 
11.44 

22.84 
'7-39 
15-25 
27.47 
29-25 
33  •  49 
44-3° 

1902  October  5.                                                                                                                  Seeing  good. 

21     5 
21   57 

a 
b 

g 
s 

X 

D 
m 
E'*, 

C' 
B'  as 
A'a, 
A' 

B'  ay 

C' 
E'a, 
m 
D 

X 

s 

g 

b 
a 

19.9    20.9    21  .  I 
22.9    23.2    23.2 
30.3    30.1    30.4 
40.3   41.9    41.7 

47-5-47-5  46-7 
40  .  8  40  .  2  40  .  5 
33-3   34-6  34.1 
12.9   13.2    12.9 

H-3   H-3   H-O 
16.8   16.5   16.8 
25.1    24.7   25.0 
6.5     6.9     7.1 
15.0  15.3   16.8 
14.1    15.2   14.2 
lO.j    12.2    II-7 

3'-8  33  5  33-2 
37-2  37-0  36.7 
43-8  43-9  43-7 
40.8  38.8  39.8 
30.8  31.3  30.6 
23.7  23.2  22.8 

22.2    21.7    21.5 

20.63 
23.  io 
30.27 
41-43 
47-23 
40.50 
34.00 
13.00 
14.  20 
16.70 

24-93 
6.83 
15-70 

14-50 

11.47 

32-50 
36-97 
43.80 
39.80 
30.90 
23.23 
21.80 

21  .72 
23."7 
30.59 
40.62 

45  52 
38.74 
33-26 
12.24 

14-35 
1  6.  20 

I  .80 
2  .04 
2.71 
3.85 

4-39 
3-64 
3  .00 
0.70 
0.91 

I  .  22 
2.  19 
0-15 

9.62 
9.86 
10.53 
n  .67 

12.21 
II  .46 
10.82 
8.52 
8-73 
9.04 
IO.OI 

7-97 

10.04 
10.28 

J0.95 
12.09 
12.63 
11.88 
ii  .24 
8-94 
9   15 
9.46 
10.43 
8-39 

1903  November  io.                                                                                                                        Good. 

21     7 

21     27 

29 
32 

a 
b 

g 
s 

X 

m 
m 

X 

s 

g 
b 
a 

</a, 

18.9   18.2   19.0 

19.6    20.3    20.  O 
26.O    26.4    26.1 
35-8    36.0    35.3 
42.0    41.2    41.5 
30.2    30.3    30.2 
30.7    30.2    30.0 
41.7    41.3    41.6 
36.0    35.2    34.2 
25.2    26.O    25.8 

18.8  18.7   19.0 
18.7   18.3  17.8 
8.0    9.1     9.0 

18.70 

19-97 
26.  17 
35-70 
41-57 
30.23 
30.30 
41-53 
35-13 
26.00 
18.83 
18.27 
8.70 

18.49 
19.40 
26.09 
35-42 
41.55 
30.27 

LSI 
1.63 
2-30 
3-23 

3-95 
2.68 

9.70 
9.82 
10.49 
ii  .42 

12.  14 
10.87 

IO.  12 

io.  24 

lO.gi 
II  .84 
12.56 
11.29 

CHAPTER   VIII. — S  i,YRJE. 


107 


TABLE  64. — 6894  S  LVRJB.     PHOTOMETER  MEASURES  OP  COMPARISON  STARS. — Continued. 


1902  November  3.                                   40-INCH,  WEDGE  V.                Seeing  poor  and  getting  worse. 

Sidereal 
Time. 

Zen. 

Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Wean  of  3. 

Mean  of  6. 

H. 

P. 

h    m 
23  26 

^ 

X 

z 

V 
ft 
a 
a 

•v 

Z 
% 
S 

33-0  33-i   34-9 
36.0  37.1  36.1 
44.8  43.8  43.8 
57-4  56-4  56-4 
59-2  59-i   58-3 
58.6  58.2  58.2 
58.2  58.7  57.2 
56.5  56.6  59.8 
44-8  44.0  45.7 
41  .8  43.2  41  .0 
34.0  35.0  35.0 

33.67 
36.40 

44-13 
56.73 
58.87 
58.33 
58.03 
57-63 
44.83 
42.00 

34-67 

34-  17 
39.20 
44.48 
57-18 

58.18 

3.10 
3  69 

4.  26 
5-35 
5-43 
5-41 

H-57 
12.  16 
12.73 
13.82 
13.90 
13  88 

11.99 
12.58 

I3.I5 

14.24 

I4.32 
14.30 

1902  October  31. 

21  30 

22       0 

S 
X 

Z 

•v 
ft 

a 
a 

ft 

•v 

Z 

•x 

S 

28.3  30.0  30.3 
32.2  33.2  33.2 
37-8  39.4  40.8 
53-5  52.8  52.3 
57-2  54-5  55-6 
53-0  50.8  53.0 
50.7  46.2  47.8 
50.2  50.2  51.3 
53-o  52-5  52  3 
38.0  39.5  37-8 
33-7  32-8  33.2 
28.0  29.2  29.4 

29-53 
32.87 
39-33 
52.87 

55-77 
52.27 
48.23 

50.57 
52.60 

38.43 

33-22 

28.87 

29.20 
33-05 
38.88 
52-74 
53.'7 
50.25 

2.57 
2.99 
3-64 
5-05 
5-°9 
4-83 

11.66 
12.08 

12.73 
14.14 
14.18 
13.92 

12.08 
12.50 
I3.I5 
I4.56 
14.60 
14.34 

1902  October  31.                                                                                                                          Seeing  fair. 

22    28 

S 
X 

Z 
V 

ft 

a 
a 

ft 

•o 

Z 
X 
S 

27.0  29.7  31.1 
32.0  32.8  32.0 
37.7  38.6  40.0 
51.7  52.8  52.3 
56.0  56.7  56.7 
54-5  55-0  55-2 
58.2  56.5  57.5 
55.2  56.0  56.0 

56.5  57-3  55-0 
44.0  43.9  43.0 
39  5  37-8  39-9 
33  9  34-0  35   i 

29.27 
32.27 
38.77 

52.27 
56.47 
54.90 
57.40 

55-73 
56-27 

43-63 
39-07 
34-33 

31.80 

35.67 
41  .20 

54-27 
56.10 

56.15 

2.84 
3.26 

3-9' 
5-i8 
5-30 
5  30 

11.66 
12.08 

12-73 
14.00 

14.  12 
14.12 

12.08 
12.50 

"3-15 

14.42 

14.54 
"4-54 

1904  May  20.                                                                                                                                          Good. 

14  50 
>7     5 

a 
ft 

Z 
X 

Z 

ft 

a 

•Tai 

45.2  47.4  46.5 
52.0  53.0  52.9 
37.0  38.6  37.0 
28.8  29.7  29.9 
38.7  36.9  37-3 
55-8  55-9  57-8 
48.8  46.8  47.2 
14.7   14.8   14.1 

46.37 
52.63 

37-53 
29.47 

37-63 
56.50 
47.60 
14.53 

46.99 
54-57 

37-58 

4-53 
5-20 
3-50 
2.60 

14.  II 
14.78 
13.08 
I2.I8 

14-53 
15.20 
I3.50 
I2.6O 

i  .00 

10.58 

II  .OO 

io8 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABUS  65. — 6894  S  LYR^E.    CONSTANTS  FOR  REDUCTION  AND  COMPARISON  WITH  CATALOGUE 

MAGNITUDES. 


6-INCH. 

Star. 

November  7. 

November  8.                                November  24. 

C. 

Obs.  Mag. 

J  Mag. 

C. 

Obs. 

Mag. 

J  Mag. 

C. 

Obs. 

Mag. 

J  Mag. 

H.  P. 

H. 

P. 

H. 

P. 

H.       P. 

H. 

P. 

H. 

P. 

E'..  . 
G'..  . 
H'.  .. 

Means 
M0.  .. 

O.OI 

0.62 

0.27 

6.86  7.28 
7-47  7-89 

7-12  7-54 

—  .02 

+  .07 
+  .04 

+  .04 
-  .08 
+  .04 

0.17 
0.65 
0.26 

6.96 

7-44 
7-05 

7.38 
7.86 

7-47 

+  .08  +  .14 
+  .  04  —  .  1  1 
—  .11  —  .  03 

O.  I  I 

0.63 
0.32 

6.91 

7-43 
7.12 

7-33 
7.85 
7-54 

+  .03 
+  .03 
-  .04 

+  .09 

—  .  12 
+  .04 

0.30 

7-15  7-57 
6.85  7.27 

±.04 

±.05 

0.36 

7.'5 
6.79 

7-57 
7.21 

±  .08  ±.og 

o.35 

7-iS 
6.80 

7-57 
7.22 

±.03 

±  .08 

12-INCH. 

40-INCH. 

Star. 

Mag. 
6-inch. 

C. 

Star. 

Mag. 
12-inch. 

C. 

July  7.     Oct.  5. 

Nov.  10. 

Oct.  31.  Oct. 

31- 

Nov.  3. 

May  20. 

a  

9.71 
9.89 
10.39 

2.41          i 

2.58               2 
3.02              2 

80 
04 
71 

1-51 
1.63 
2.30 

g 

s  . 

10.46 
11.56 
12.  18 

6  

2-57            2 

2.99        3- 

84 
26' 

3  10 

3.69 

2.60 

X 

M 
M 

M 

Mean  C  . 
Mean  Mag 
Mn 

san  C  .  .  . 

IO.OO 

2.67              2 
IO.OO           1O 

7-33          7 

18 
oo 

82 

1.81 

IO.OO 

8.19 

2.78        3. 
1  1  .87      n. 
9.09         8. 

05 
87 
82 

3  40 

11.87 
8.47 

2.60 

12.  18 

9-58 

•;ui  Mag. 

.If 


MAGNITUDE,, 

'-*  H 


6894-  S  LYRA.E 


FIG.  22. — MAGNITUDE-CURVE  FOR  S 


CHAPTER   VIII. — S   LYR^E. 


109 


TABLE  66. — 6894  S  LYUUB.    MEAN  MAGNITUDES  OF  COMPARISON  STARS. 


6-INCH. 

Star. 

November  7. 

November  8. 

November  24. 

Mag. 

A  Mag. 

Mean. 

Mag. 

A  Mag. 

Mag. 

A  Mag. 

Mag. 

A  Mag. 

Mag.  H. 

Mag.  P. 

4  Mag. 

£'.. 
G'  ... 
H'  .. 

a.  ... 
b.... 
g.... 

6.86 
7-48 
7.12 

Mean. 

9-79 
9.92 
10.44 

Mean 

—  0.05 
+  0.03 

+  O.O2 

6.96 

7-44 
7-05 

+  0.05 

—  O.OI 

-0.05 

6.91 

7-43 
7.12 

o.oo 

—  O.O2 
+  O.O2 

6.91 

7-45 
7.10 

7-33 
7.87 
7-52 

±0.03 
±0.02 
±0.03 

7-15 

7-57 

±0.03 

+  0.08 
-4-0.03 
+  0.05 

9-63 
9.86 
10.32 

—  0.08 
-0.03 
—  0.07 

9.71 
9.88 
10.42 

O.OO 
—  O.OI 
+  0.03 

9.71 
9.89 
10.39 

10.13 
10.31 
10.81 

±0.05 
±0.02 
±0.05 

IO.OO 

10.42  |   ±0.04 

12-INCH. 

Star. 

July  7. 

October  5. 

November  10. 

Mag. 

A  Mag. 

Mean. 

Mag. 

A  Mag. 

Mag. 

A  Mag. 

Mag. 

A  Mag. 

Mag.H. 

Mag.  P. 

A  Mag. 

a  
b  
g  

s.  .  .  . 

9-74 
9.91 

10.35 
Mean. 

11.58 

+  0.05 
+  0.05 
—  0.09 

9.62 
9.86 
10.53 

—  0.07 
o.oo 
+0.07 

9.70 
9.82 
10.49 

+  O.OI 

—  0.04 
+  0.03 

9.69 
9.86 
10.46 

IO.  I  I 

10.27 
10.88 

±0.04 
±0.03 
±0.06 

IO.OO 

10.42 

±0.04 

+  O.O2 

ii  .67 

12.21 
10.82 
II  .46 

+  O.  II 

+0.03 
—0.08 

ii  .42 
12.14 
10.87 

—  o.  14 
—  0.04 
-0.03 

II  .56 
12.18 
10.90 
II  .46 

11.98 
12.60 
11.32 
11.88 

±0.09 
±0.02 
±0.08 

m  .  .  . 
n 

u  .02 

+  0.12 

Mean  • 

"•55 

"•97 

±0.06 

40-INCH. 

Star. 

October  31. 

October  31. 

November  3. 

May  20. 

Mean. 

Mag. 

A  Mag. 

Mag. 

A  Mag. 

Mag. 

A  Mag. 

Mag. 

A  Mag. 

Mag.  H. 

Mag.  P. 

JMag. 

s.  .  .  . 
x.  .  .  . 

i.  .  .  . 

a  .... 
ft.  ... 

11.66 
12.08 

Mean. 

12-73 
13.92 
14.  18 

+  0.03 
—  0.04 

11.66 
12.08 

+  0.03 
—  0.04 

11-57 

12.  l6 

—  0.06 
+  0.04 

12.  18 

+  0.06 

11.63 

12.12 

12.05 
12.54 

±0.04 
±0.04 

11.88 

12.30 

±0.04 

—  0.09 
—  0.09 

12.73 

14.  12 
14.  12 

—  0.09 

+  O.II 

12.73 
13-88 
13.90 

—  0.09 
-0.13 

13.08 
14.  ii 
14.78 

+  0.26 
+  o.  10 

12.82 
14.01 
var? 

13-24 
'4-43 

±0.13 

±O.  I  I 

no 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABLE  67. — 6894  S  LYR.B.     VISUAL  OBSERVATIONS  OF  THE  VARIABLE. 


No. 

Date. 

b 

JS 

Aperture. 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing. 

t. 

J  Mag. 

Month 
and  Day. 

Hour 
C.  S.  T. 

Julian 
Day 
G.  M.  T. 

Steps. 

Mag. 

i 

2 

3 
4 
5 

6 

7 
8 

9 
10 
ii 

12 
13 
14 
15 

16 

17 

18 

19 

20 

21 
22 

23 

24 

25 
26 

27 
28 

29 
30 
31 
32 

33 
34 
35 

36 

37 
38 
39 
40 

4' 
42 
43 
44 
45 
46 
47 
48 
49 
50 
5' 
52 
53 

1896 
Oct.      7 

Nov.  12 

26 

Dec.     9 
23 

1897 
Jan.      9 
May  25 
June  ii 
July     i 
16 
26 
Aug.  27 
Sept.  17 

22 

Oct.    25 
Nov.  1  6 
Dec.   29 

1898 
Feb.    15 
Mar.     2 

Apr.      i 

15 

May     7 

21 

June  14 
27 
July    5 
18 
Aug.     i 
18 
Sept.    7 

20 

Oct.      8 
Nov.     i 
15 

1899 
Mar.   22 
Apr.   21 
May     i 
18 
29 
June     7 
'3 

July    5 

July   10 
18 
Aug.     5 
10 
26 
Sept.    4 

12 

26 
Oct.     4 

23 

7 
6 
6 

9 

10 

9 
9 
9 
9 

8 
8 
8 

7 
6 
6 

17 
17 
16 
16 
16 
10 

9 

ii 
ii 
10 

IO 

8 
8 

6 

7 

16 
16 

IO 
IO 

9 

10 
10 
10 
10 

9 
9 
9 
9 
9 
7 
8 
8 
7 

2410000+ 
3840 

3876 
3890.54 
3903-50 
3917.50 

3934.63 
4070.67 
4087  .  63 
4107.63 
4122.63 
4132.63 
4164.58 
4185.58 
4190.56 
4223-54 
4245-50 
4288.50 

4336  96 
4351-96 
4372.92 
4381.92 
4395-92 
4417.67 

4431-63 

4455 
4468 
4476.71 
4489.71 
4503-67 
4520.67 
4540.58 
4553-58 
4571-54 
4595-50 
4609.54 

4736.92 
4766.92 
4776.67 

4793-65 
4804.63 
4813.67 
4819.65 
4841  .67 
4846.65 
4854.61 
4872.63 
4877.61 
4893.61 
4902  .  6  i 
4910.54 
4924-56 
4932  •  56 
4951-54 

80 

150 
150 
150 
150 

80 
150 
150 
150 
150 
150 
150 
80 
150 
150 
150 
150 

150 
150 
150 
150 
150 
40 
1  40 
(150 
80 
80 
80 
80 
80 
80 

'So 
150 
200 

200 
150 
200 
150 
150 
150 
150 
150 
150 
150 
«5o 
150 
150 
150 
150 
'So 
'So 

6 

6 
6 
6 
6 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

6 
6 
6 
6 
6 
6 
6 
6 

12 
12 
12 
12 
12 
12 
6 
6 

6 
6 
6 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

(a2b,   btf,  /2g,  g$h,  hik,  kl 
-•'giq,  qr,  gj,p,  p2tn,  mn,  no 

) 

<2I 
<2I 

<i8 

<i8 

21  .O 

28.0 
26.1 
24.2 
20.3 
20.2 

'97 
17-4 
12.4 

8.9 
<i9 
<n 
<n 

<i8 
20.  o 

26.7 
31.5 
31.9 
32.0 

32.4 

27.8 

31     2 
26.8 
26.8 
25.2 
21.3 
18.3 
17-5 
17.2 
IO.4 

<n 

<i7 
18.2 
20.  o 

21.5 

23.7 
25.7 

29.6 

33-  ' 
30-9 
30  9 
30-9 
28.6 
28.6 
26.9 

25-7 

24.4 

22.8 
2!.  6 

<ii.6 
<n.6 

<I2.I 
<I2.I 

11.68 

10.  72 

10  99 
11.25 
11.77 
11.78 
11.86 
12.15 
12.79 
13-25 
<ii-9 
<i3-o 
<I3  o 

<I2.I 

1  1.  80 
10.91 

IO.2O 
IO.I7 

10.  16 
10.09 

10.77 

10.  27 
10.90 
10.90 
II  .  IO 

11.62 
12.03 
12.13 
12.17 
13.03 

<i3-o 

<I2.2 
12.05 
11.80 
II.  6O 
11.32 

11-05 
10.50 

9  99 
10.31 
10.31 
10.31 
10.65 
10.65 
10.89 
11.03 
ii  .20 
ii  .42 
ii  59 

good 
good 
moon 
good 

low 
good 
good 
good 
good 
fair 
fine 
fine 
fine 
good 
fine 
good 

good 
fine 
good 
good 
good 
fair 

fair 

fair 
good 
good 
fair 
moon 
fair 
good 
fair 
fine 
good 
good 

good 
low 
low 
good 
low 
good 
good 
good 
moon 
fair 
good 
good 
good 
good 
good 
poor 
good 

o 

36 

77 

94 
230 

247 
267 
282 
292 
324 
345 
350 

76 
96 
1  06 
1  20 

HI 
155 

179 
192 
200 

213 
227 

244 
264 

277 
295 
3i9 

54 
64 
81 
92 

IOI 

107 
129 
134 
142 
160 

165 
181 
190 
198 

212 
2  2O 
239 

+  0.  II 

-0.36 

—  O.2I 

—  o.  24 

—  0.09 

-0-34 
—  0.46 
-0.85 

-0.66 
-0.27 

+  0.20 
-0.13 
-0.59 
-0.31 
—  0.05 

—  o.  14 
+0.30 

—  0.46 

+0.13 
—  0.07 
—  0.07 
+0.32 

+  O.22 
+  O.  IO 
-0.23 

+  o.  15 

-0.25 

—  o.  18 
+  0.18 
+  0.15 
+  0.15 
—  0.29 

-0.33 
+  0.04 

+  O.  IO 

+  o  03 

+0.33 
+0.15 
+0.29 
+0.32 
+0.27 
+0.35 
+0.26 

) 

Uiw  UT,—4.t 

04—57',  657;,  7)3/  vih 

29.7,  29.0,  27.6,  26.6 
25.6,  26.6  

g57),  vim  ...  . 

7/4  s,  01—  2v,  m2v  

VS,  V2X  m6v 

25.0,  24.2,  23.6.  ... 

21  .O,  2O.4,  19.6.  ... 

SIV,  V2X  
SIV,  VIX  

xiv  v  glimpsed 

20.  o,  20.4  
20.  o,  19.4  

*3-47>±,  zi-27)  
.22—  37;,  V  glimpsed 

14-9,  99  

v  not  seen,  limit  1-2  <  A 

i)  not  seen,  limit  z 

11  not  seen  limit  x 

7140,  7)2  s,  Div,  »t3—  47)  
7)2  wt,  vi  n,  7)6$  £47)  , 

15.4,  23.0,  20-5,  22.  I 

27-6,  25.7,  27.0,26.6 

30.7,  31.6,  32.3.  ... 
32.6,  31.3  
31.2,  32.3.  32.6.  ... 

32.3,  33-6  > 
31-3.  32-6  j 
28.6,  27.  i  

v(>n,  vig,  &27)  

7)2g,  637;  ,  
0471,  6271,  7>2g  

627;,  7<3g  

b$V,  V2g  
g2V,  V1-2W  

64-571,  V2g,  limit  3  <  z  
g4-57),  V2m,  c8a,  eioa  

g4T>,  7)1  —  2m  

g47>,  mzv,  Tin  . 

29-8,  32.6  
26.  i,  27.6  
26.6,  27.1  
26.6,  23.6,  25.6..  .. 

19.6,  22.  O,  22.4.  ... 
18.6,  19.0,  20.4,  15.  .( 

m6v,  vis,  v^x,  limit  z  
mf>—  87),  S2v,  Ti2x,  7142,  limit  z  . 
v  glimpsed,  $3—  47;  .... 

S2v,  vx,  7>3z,  limit  z  
zii),  v  glimpsed 

19.0,  18.4,  14.4..  .  • 

v  not  seen,  limit  z 

v  not  seen  limit  1—2  <  x 

v2—  3z,  vix,  vs,  Dyv  

.13.9,  19.4,  21.0,  18.5 
2O.O,  2O.O  

23-5,  '95  
24.0,  24.6,  22.5..  .. 

25.0,  26.6,  26.  I  .... 

28.1,  30.6,  30.3  — 

33  3,  33-'  
30.3,  3'.6  
30-3,  3'.6  

SIV,  V2X  

7)2-3$,  D2V,  uncertain  
7)3$,  mm,  viD  
7)4/2,  vim,  £4—57? 

7>2—  3»t,  7>g,  647)  
637>,  7>2-3g  

6471,  7)ig  
6471,  7>ig  

b6v,  g2-yv,  V4m  
g27>,  -ayn  
g47),  vim,  716-7$  
g47),  vm,  7)4$  
g7~  871,  vm,  713—4$  
m2v,  vis  

TO2-37),  7IO-I$,  V2X  

28.3,  28.  i,  29.6..  .  . 
28.6,  28.6  
26.6,  26.6,  27.5..  .. 
26.6,  25.6,  25.0.  ... 
23.1,  25.6,  24.5...  . 

23.6,  22.0  
23.1,  21.5,  20.4-.  .  . 

CHAPTER   VIII. — S   LYR^E. 


Ill 


TABLE  67.— 6894  S  LYR.B.     VISUAL  OBSERVATIONS  OP  THE  VARIABLE. — Continued. 


No. 

Date. 

Ocular. 

V 
B 

i 

B 

B. 

< 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing. 

t. 

J  Mag. 

Month 
and  Day. 

Hour 
C.S.T. 

Julian 
Day 
G.  M.  T. 

Steps. 

Mag. 

54 
55 
56 

57 

58 
59 
60 
61 
62 
63 
64 
65 
66 

67 
68 
69 
70 
7' 
72 
73 
74 
75 

76 

77 
78 
79 
80 
81 
82 
83 
«4 

85 
86 

87 

88 
89 
90 

91 
92 

93 
94 
95 
96 
97 

98 
99 
too 

IOI 

iS99 
Oct.   30 
Nov.     6 

20 
22 

igOO 

Feb.   24 
Mar.     2 

22 

Apr.     4 
6 
May      2 
IT 
28 
29 
June  19 
28 
Aug.     6 

13 
20 
Sept.    5 

15 
Oct.    26 
Nov.  21 

1901 
Nov.  12 

1902 
Mar.     5 
28 
May    14 
July     7 
Oct.      5 

10 

20 

3i 
Nov.     3 
Dec.      i 
23 

1903 
Oct.    10 
ii 
13 

1904 
May    17 
20 
Aug.     4 
27 
Sept.  24 
Oct.      8 
Nov.  30 

1905 
Jan.      3 
Feb.    14 
Mar.   12 

Apr.      4 

6 
6 
6 

7 

18 
16 
IS 
i5 
16 

'5 
14 
10 

12 
12 
IO 

9 
9 

8 
8 

7 
6 
6 

7 

16 
'4 
13 

10 

9 
9 

8 

7 
8 

7 

IO 

7 
9 

ii 

9 
8 

8 
IO 

6 

6 

17 
16 

16 

2410000+ 
4958.50 
4965  •  50 
4979-50 
4981.54 

5075  98 
5081.92 
5101.85 
5114.88 
5116.92 
5142.88 
5151-83 
5168.67 
5169  75 
5190  75 
5I99-67 
5238-63 
5245-63 
5252-58 
5268.58 
5278-54 
5319  50 
5345  •  50 

5701-54 

5814.92 

5837-83 
5884.79 
5938.67 
6028.63 
6033.63 
6043.58 

6054.54 

6057  .  58 
6084 
6107.54 

6398.67 

6399-54 
6401  .63 

6618.71 
6621  .63 
6697.58 
6720 
6748.58 
6762.67 
6815.50 

6849.50 
6891  .94 
6917.94 

6940.92 

150 
150 

200 

175 
275 
350 
275 
35° 
460 
460 
275 
237 
350 
237 
150 
150 
40 
40 
150 
150 
150 

350 

237 
237 
67 
67 
67 
237 
237 

237 
237 

237 

67 
150 
80 

40 
237 
150 
150 

237 
40 

750 
750 
750 
(237) 
*75oi 

6 
6 
6 
6 

12 
12 
40 
12 
40 
40 
40 
12 
40 
40 
40 
6 
6 
6 
6 
6 
6 
6 

40 

40 

40 

12 

12 
12 
40 
40 

40 

40 

24 
40 

12 

6 

12 

6 

40 

6 
6 

24 
40 
6 

40 
40 
40 

40 

m6v,  vs  

S2V,  VO-IX  

v  not  seen,  limit  2  <  s  

S211,  V2X,  7TJ2      

v  suspected,  limit  4  <  z 

19.6,  21  .0  
19.0,  18.9  

20.3 
18.9 
<I9 
17-9 

<   7 

<   6 
0.6 

2 
-     4.0 
-     4.0 
-     4.0 

<   6 
3-3 
7-8 
12.4 
23-5 
26.5 
30.6 
32-5 
31-8 
3«-9 
28.1 

26.6 

24.6 
21.4 
<i8. 
7-9 
<n 
i± 

11.77 
11.96 
<n.g 
12.08 

03-5 
<J3-6 
14.27 
14.  i± 
14.87 
14.87 
14.87 
<i3-6 
'3  95 
'3-39 
12.78 

"•35 
10.95 
10.35 
10.07 
10.  19 
10.  18 
10.70 

10.94 

ii.  19 
ii  .60 

<I2.I 

I3-38 

<i3  o 

14.  2± 
I4.O2 

14.07 

13-82 
15-0 
11.87 

<I2  .  2 

•O3  o 

<I3-« 
IO.2O 

9-74 
ii  .76 
12.03 

H 
13.2 

<I2.I 

14.67 
15-05 
14.87 

H  59 

fair 
good 

246 
253 

+  0.28 
+  0.34 

19.0,  20.4,  14.4  

good 

fair 

good 
good 
fair 
fair 
fair 
good 
good 
poor 
good 
moon 
good 
poor 
fair 
good 
good 
poor 

good 

fair 
good 
good 
good 
good 
moon 
fair 

fair 
poor 

good 

moon 
good 
good 

good 
good 
fair 
good 
fair 
fair 
good 

fair 
fair 
fair 

good 

269 

389 

404 
430 
3 

21 
42 
51 

90 
97 

IO2 
1  2O 
130 

17! 
'97 

"7 

231 
253 

354 

8 

13 

23 

34 

37 
64 
87 

89 

162 
'65 
241 
266 
292 
306 

393 
o 

25 

48 

+0.18 

-0.13 

+  0.18 
+  0.06 

+  O.  IO 

—  0.40 
+  0.51 
+  0.38 
+  0.15 
-0.05 

-0.54 
—  0.42 

—  O.  II 
—  O.2I 
—  O.O2 

+  0-39 

—  O.O4 
—  O.O2 

-0.25 
—  O.O4 

-0.18 

+  0.77 
+  0.63 

+  0.57 

—  O.  IO 

-0.58 
+0.25 
+0.19 

+  o.5± 

• 

| 

4-0.17 
+  0.25 
+0.77 

+  1.99 

v  not  held,  limit  5  <  z 

«27),  7)10  

0.3,  i  .0  

7;  or  a  glimpsed   at  limit 

28—  io«,  «^—  40,  047; 

27—  8«,  ai#,  £47;  . 

020   047;  26  Sa 

TI  not  seen,  limit  5-6  <  z 

ZIW,  7>3<»     «I—  2fl 

I  .  4.    S  .  "V  .              

041),  7)6«,  03-4^  
x6v,  -viz  
myv,  -v-zD,  v6x  
•vf>--js,  ti^m,  v$D,  tin  
T^tn,  i)g 

7-4,  8.3  
12.4,  12.4  
22.6,  23.5,  24.4  
27.5,  28.6,  25.5,  24.7 
3o  6    ^o  .  6  .          .... 

037;,  61-27;,  -D3g  
byv,  vg,  T>6m  

31.2,  32.8,  33.6  
33-3.  30-6,  31.6  
3i-2,33-  3,31-6,30-6 
26.6,  29.6  

037;,  biv,  vig,  tiftm,  

g47>,  z>4»t  
24—57;  

m27J,  7)4/7   .  .    . 

2l6     2  ^     ^ 

vyc,  vs,  vD,  myv 

21  .4,  21  .O,  21  .5,  21  .6 

1}  not  seen,  x  seen  . 

23-47;,  v  glimpsed   

v  not  seen,  limit  2  

7Ja4j,  7)0J-    

2±,  O± 

photometer  

f  photometer.                   ) 

photometer  

photograph  

S2T1,  112X  

"v  not  seen   limit  i  <  x 

ig.O,   20.4  

19.7 

<i7 
<n 

<IO 

3«-7 

"v  not  seen,  limit  z 

v  not  seen,  limit  i  <  2 

63-47;,  V2g  
photometer  

30.8,  32.6  

siv  v2—yc 

20.  o,  20  9  

20.4 
18.2 

syv,  vx  
photographs    .... 

18.0,  18.4  

247;,  7MO-I20,  050  

v  not  seen   limit  x 

7-4,  13-3  

9± 
<i8 

-2.5 
-5-5 
-4.0 

0.0 

a^—  40,  05—67;  near  limit 

«40,  047>          

f  "2-37;,  ri0  

—  0.2,    I.O  ) 

\  147;,  7)0  

-1.7,  o.o  ) 

112 


RESEARCHES   IN  STELLAR    PHOTOMETRY. 


TABLE  67. — 6894  S  LYR.S.    VISUAL  OBSERVATIONS  OF  THE  VARIABLE. — Continued. 


No. 

Date. 

Ocular. 

Aperture. 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing. 

/. 

J  Mag. 

Month 
and  Day. 

Hour 
C.  S.T. 

Julian 
Day. 
G.  M.  T. 

Steps. 

Mag. 

102 

103 
104 

105 
1  06 
107 
1  08 
109 

no 

I  II 

112 

U3 
114 

"5 

116 
117 

118 
119 

'90S 
Apr.    1  1 

30 
May  20 
June  13 

20 

24 
26 
July   23 
26 
Aug.    9 

21 
22 

25 
28 

Sept.  17 
Oct.      i 
20 
Nov.  1  8 

16 

14 
10 

H 

12 

9 

IO 
IO 

9 
9 
9 
9 

IO 

8 
7 

10 

7 
6 

2410000+ 
6947.92 

6966.83 
6986.67 
7010.83 

7017-75 
7021.63 
7023.67 
7050.67 

7053-63 
7067.63 
7079-63 
7080.6 
7083.67 
7086  59 
7106.55 
7120.67 

7'39  54 
7168.50 

750 

237 
237 
237 
237 
80 
80 
237 
150 
>50 

150 
150 

237 
80 
237 

40 

40 
40 
40 
40 

12 
12 
40 
6 

6 

12 
12 
12 

6 
6 
40 

12 
40 

/  7)43,  1)1",  Z  is  2"    >    V.  ..\ 

(  z8i>,  7)4"  ) 

4    O   1    ^  .  . 

3-5 

5-3 
15-4 
30.6 

32.4 
25  9 
28.4 

'3-9' 

13  69 

12.40 

i°  34 
10.  06 
n  .01 
10.67 
to.6± 
1  1.  20 
10.79 
<io.5 
n.  7 
11.7 
n  .  16 
11.41 
11.85 
11.71 
«3  05 

good 

good 
good 
good 
good 
poor 
good 
good 
good 
good 
fair 
good 

good 
good 
fair 
good 
good 

55 

74 
94 
118 

125 
129 

«3' 

158 
161 

175 
187 
1  88 
191 
194 
214 
228 

247 
276 

+  1.60 

+  2.O7 

+  1-31 

-0.17 
-0.32 

+0.68 
-0.37 
+  o.3± 
+0.90 

+  0.37 

+  1.1 
+  1.1 
+0.46 
+  0.42 
+  0.65 

+  O.  21 
+  I.O2 

3.4,  6.3.  

z&v,  7/4*  

X2TJ    1/32     

l6.4..    14.    A. 

T)tr  4- 

b2—W.  V2.~\e  .  . 

11  .8.   11.  I.  . 

25  6    26   i 

g2V,  TJ2-3W  

photometer  

28.6,  28.  I  

miv,  "V2D,  1/4—  $s  
g4vt  v^m  
photographs   213,  214  .    . 

24.6,  23.6,  25.5  
26.6,  28.6  

24-3 
27.6 

photographs,  215,  216  

photographs,  221,  222  

24.7 
22.9 
19.7 
20.7 
10.4 

1TI2V,  VlD,  VI-2S  
S2V,  V2X  

23.6,  22.5,  22.5  
19.0,  20.4  

CHAPTER   VIII. — S   LYRA. 


00 

°  o 


ei 


CO 
°> 


p 

2 


Fio.  33. — LIGHT-CURVE  OP  S  Lvn*. 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABLE  68. — 6894  S  LYR^E.    MEAN  MAGNITUDES  PROM  36$  DAY  GROUPS. 


Group  No  
J     D  

i 

16 

2 
77 

3 

IOQ 

4 

145 

5 
182 

6 

218 

7 
254 

8 
291 

9 
327 

IO 

363 

:i 

400 

12 

436 

r       t 

8s 

2-<8 

272 

108 

-148 

M 

I  I      2O 

I  I  .  I  2 

II    .78 

12  .OO 

13  .  O2 

3840  \      JM 

—  O.  12 

—  O.22 

—  O.  22 

-0.66 

—  o.  46 

I.     No 

2 

2 

2 

2 

2 

f         t 

167 

202 

2^.6 

27O 

7Q7 

M 

IT     -?6 

12    08 

12    60 

4*76  i      JM 

—  O    17 

o   18 

—  o  08 

O    I  1 

+  O    12 

+  o.  16 

—  o  04 

L     No 

2 

2 

2 

47-  (     A 
I     No. 

r        t 

I  2 

59 
ii  .92 

—  O.22 
•  2 

46 

95 

II.  12 
+  0.05 

4 
96 

135 
10.20 
—  O.O6 

3 

125 

169 

10.54 
4-0.17 

3 

171 

200 
ii  .04 
+  0.29 
3 

IO7 

240 
11.68 
+  0-3I 

4 

269 
12.08 
4-0.18 
I 

389 
14.27 
-0.13 
i 

417 
14.87 
4-O.  12 

2 

M 

I  7    08 

10  85 

10  18 

5'4«i      jJJ 

O     I  5 

—  O    21 

1     No 

2 

•a 

2 

I 

f         t 

117 

242 

"*54 

M 

j-i  -18 

5584  ^      JM 

-l-O    1.Q 

—  o  ot 

—  O    2S 

No 

2 

I 

r     < 

21 

•57 

87 

M 

14  10 

n  82 

ii  8? 

6020         JM 

+  o  06 

+  o  63 

-4-O    57 

L     No 

r    * 

164. 

24.1 

266 

^06 

•3Q-1 

M 

9,07 

II  .  76 

12  .03 

IV2± 

14.67 

645«  j      JM 

~f~o  25 

4~O    19 

4-o  5± 

—  O    17 

L     No 

I 

i 

!( 

25 

M 

14.    8? 

JM 

4-o    77 

No 

I 

r     i 
Means  i  JM 

t    No. 

20 

14.46 

-fo.  13 
8 

47 

12.  6l 
+  O.2I 

5 

91 
II  .20 
-0.03 
13 

127 
10.36 

—  O.  IO 

8 

168 
10.28 
—  0.06 

8 

2OO 
I0.8l 
4-0.07 

7 

239 
ii  .46 

4-o.  ii 
ii 

270 

11.99 

+  0.04 
6 

307 
12.48 
—  0.26 
5 

35  » 
13  20 

-0.39 

3 

391 
14-47 
4-O.O2 
2 

4'7 
14.87 

4-o.  12 

2 

CHAPTER   VIII. — S   LYR^E. 


10 


too  zoo 


DAYS 


400  500 


12 


u 

Q 

i 

<s 


6894  S  LYRAE 
j 

Miii'-4Z9d 
M-m~IS4d 


/4 


/s 


FIG.  24. — MEAN  LIGHT-CURVE  OF  S  LYR.S 


n6 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABLE  69. — 6894  S  LYRB.  OBSERVED  MAXIMA  AND  MINIMA. 

Elements  of  maximum.      1898    May  12  (J.  D.  2414422)+  438*  (E-4).     M-m^l 


MAXIMA. 

MINIMA. 

I 

W 

Date. 

Mag. 

Corr. 

wt. 

t 
W 

Date. 

Mag. 

Corr. 

Wt. 

Calendar. 

J.  D. 

H. 

P- 

Calendar. 

J.D. 

H. 

P. 

3 

4 
5 
6 

7 
8 

9 
10 

1897  Mar.     4 
1898  May   12 
1899  July     7 
1900  Sept.  29 
1901    Dec.  26 
1903   Mar.  12 
1904   May  23 
1905   July     2 

3988 
4422 

4843 
5292 

5745 
6186 
6624 
7029 

me 
10.37 
10.42 
10.46 
me 
me 
me 
ii  .02 

+   4 
o 

-i? 
-    6 

+   9 

+  12 

+  12 
+  21 

7 

20 

27 

9 

3 

i 

3 
24 

4 
5 
6 

8 

9 
10 

1897  Dec.  19 
1899  Feb.  13 
1900  Apr.  25 
1901  July   14 
1902  Sept.  25 
1903  Dec.   13 
1905  Feb.  1  8 

4278 
4699 

5135 
558o 
6018 
6462 
6995 

me 

me 

I5-32 
me 

I5-32 
me 

"5-43 

+  10 
-  7 
-  9 

—  2 

+  4 

6 
6 
16 
I 
9 

2 
H 

9-95 

IO.OO 

10.04 
10.60 

14.90 
14.90 

15.01 

The  last  comparison  used  in  deriving  the  mean  light-curve  was  that  of  1905 
March  12.  The  curve  yields  a  period  of  438  days.  Several  series  of  observations, 
covering  the  maxima  between  1 895  and  1900,  have  been  published  in  the  A stro- 
nomical  Journal,  by  H.  M.  Parkhurst,  who  noted  an  "  intermediate  maximum " 
1896  July  14.  Probably  for  this  reason  the  period  which  had  been  given  as 
430  days  in  Chandler's  Third  Catalogue,  was  called  218  days  in  his  "Revised 
Elements."  The  present  series  excludes  such  intermediate  maxima  (except 
that  no  evidence  is  furnished  for  1901). 

A  single  observation  at  Bonn,  1856  July  30,  9.5  magnitude,  might  refer 
to  this  star  if  a  correction  of  one  division  of  the  ocular  scale  be  admitted.  If 
so,  the  star  must  have  been  very  near  maximum,  and  calling  the  epoch -31  the 
period  436  days  results;  but  as  stated  above,  at  present  the  period  is  at  least 
438  days. 

Leaving  out  of  account  the  intermediate  maximum  in  question,  the  light- 
curve  presents  no  abnormal  features.  The  total  range  observed  is  just  about 
five  magnitudes,  the  different  maxima  and  minima  being  quite  closely  accordant, 
The  rise  is  much  faster  than  the  decline,  occupying  but  35  per  cent  of  the  period. 


CHAPTER   IX. 

7220  S  CYGNI. 
R.  A.  2oh  31"  245.7;  Dec.  +  57°  41'  52"  (1900). 

This  star  was  discovered  at  Bonn  in  1860  and  has  been  well  observed,  since 
Chandler's  revised  elements  depend  on  43  maxima  and  5  minima,  but  it  does 
not  appear  that  the  minima  have  ever  been  completely  followed.  Townley 
reports  it  invisible  for  two  months  near  minimum  in  the  Madison  1 5-inch,  and 
in  the  extended  series  of  observations  published  in  Harvard  Annals  37  it  was 
invisible  for  periods  ranging  from  70  to  99  days.  The  photometric  measures  of 
comparison  stars  at  Harvard  extend  only  to  13.44,  and  those  by  H.  M.  Parkhurst 
to  13.48;  so  that  more  work  was  needed  in  fixing  the  magnitudes  of  the  fainter 
comparison  stars  and  following  the  variable  through  its  minimum.  In  the  Har- 
vard volume  above  cited  the  faintest  magnitudes  noted  before  and  after  minimum 
range  from  13.0  to  14.8,  and  though  opportunities  for  observation  when  the 
variable  was  faint  have  been  few,  about  a  dozen  comparisons  have  been  made 
when  it  was  below  the  Harvard  limit;  and  photometric  magnitudes  have  been 
found  for  the  comparison  stars  down  to  the  faintest  used,  thus  fixing  the  mini- 
mum magnitude  of  the  variable  with  some  precision. 

TABLE  70. — 7220  S  CYGNI.    STANDARD  MAGNITUDE  STARS. 


Star. 

B.  D.  No. 

1900. 

Color, 
P.  DM. 

Magnitude. 

Residuals. 

R.  A. 

Dec. 

Catalogue. 

Measured. 

From  Cats. 

3 
Nightc 
inter 
se. 

H.C.O. 

P.  DM. 

H. 

P. 

H. 

P. 

B 
C 
D 

+  5.7   2106 
)  57   2129 
••»  £7   2144 

Mean 

h     m       s 

19    56    58 
20    02    32 

20      05      38 

0                       / 

+  57     32-1 
+  57     19-5 
+  57     29.5 

W 
GW 

W 

7.08 
7.88 
7.04 

7-47 
7.96 

7.32 

7-29 

7-53 
7-17 

7-54 

7.78 
7.42 

+  21 

-35 

+  '3 

+   7 
-18 

+  10 

±   4 
±   6 
±n 

7-33 

7-58 

7-33 

7.58 

±23 

±12 

±   7 

TABLE  71. — COMPARISON  STARS  IN  B.  D.  CATALOGUE. 


B.  D. 

1855- 

B.  D. 

1855- 

btar. 

No. 

Mag. 

R.  A. 

Dec. 

No. 

Mag. 

R.  A. 

Dec. 

0 

h  m  s 

0      / 

c 

h  m  s 

•   / 

c 

+  57  2124 

8.9 

20  oo  23 

+  57  23.9 

r 

+  57  2137 

9.0 

20  2  44 

+  57  3°-3 

d 

+  57  2128 

9.0 

20  I  18 

+  57  36.0 

g 

+  57  2139 

9-5 

20  3  20 

+  57  29.0 

e 

+  57  2130 

9-3 

20  2  4 

+  57  3'-6 

b 

+  57  2149 

8.1 

20  6  2 

+  57  53-6 

) 

+  57  2135 

8.9 

20  2  29 

+  57  35-1 

RESEARCHES   IN   STELLAR    PHOTOMETRY. 


TABLE  72.— COMPARISON  STARS  FOR  S  CYGNI  (IN  ORDER  OF  RIGHT  ASCENSION). 


Star. 

Coordinates  from  Variables. 

Light 
Scale, 
Steps. 

Magnitude. 

R.  A. 

Dec. 

Measured. 

From  Curve. 

H. 

P. 

H. 

P. 

c 

It 

-990 

-124.4 

—  624 

39-7 

8.54 

8.79 

e 

-551 

-68.9 

+  105 

36.9 

9-39 

9-64 

a* 

-422 

-52.6 

-1342 

7-53 

7-78 

/ 

-194 

-24.2 

-152 

32.1 

9.87 

IO.  12 

a 

—  109 

-13-4 

+   72 

8-3 

13.90 

H-'S 

y 

-   74 

-    9-3 

+   52 

16.4 

12.31 

12.56 

m' 

-   45 

-   5-6 

+  455 

e 

-   41 

-    5-' 

+   80 

03 

14.94 

15-19 

i 

-   39 

-   4.4 

—      4 

-0.5 

15-48 

15-73 

15.66 

15  -9i 

X 

—    22 

-     2.8 

-165 

19.0 

n   95 

12.  20 

d 

+     3 

+   0.3 

+   45 

38.0 

8.98 

9-23 

i 

+     8 

+    i.o 

+   59 

4-8 

14.63 

14.88 

r 

.  +   21 

+    2.6 

-114 

4.6 

J4-34 

14-59 

P 

+   35 

+  4.4 

-170 

21.8 

11-43 

ii   68 

m 

+   49 

+   6.1 

+  461 

24.1 

10-73 

10.98 

I' 

+   82 

+  10.3 

-   94 

o 

+   98 

+  12.3 

+  168 

22.  0 

11.32 

"•57 

n 

-f  IOO 

+  12.5 

+  445 

23.6 

II  .  12 

"-37 

I 

+  105 

+  13-' 

—  IOO 

25-7 

10.53 

10.78 

t 

+  105 

+  13-1 

+   45 

10.6 

12.  8± 

13-1+- 

13.  5± 

13.  7± 

T 

+  125 

+  15.6 

-230 

8.86 

9.11 

k 

+  162 

+  20.3 

-347 

28.7 

IO.  2O 

10.45 

& 

+  400 

+  50.0 

-314 

33-2 

9-59 

9.84 

*o  =  c  of  Table  71. 


TABLE  73. — 7220  S  CYGNI.  PHOTOMETER  MEASURES  OP  COMPARISON  STARS. 


1904  September  3.                                            6-1  NCH.                                                                   Good. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

h   m 

o 

21      O 

19 

B 

10.0     9.7     9.8 

9-83 

10.  17 

0.30 

7-23 

7.48 

C 

12.2   11.7   11.5 

11.80 

I  2.  O2 

0.51 

7-44 

7.69 

c 

20.2    2O.  O    20.2 

20.  13 

20  88 

i  .69 

8.62 

8.87 

e 

24.9  25.6  25.3 

25-27 

26.90 

2-39 

9-32 

9-57 

f 

30.8  29.9  30.3 

30.33 

30.67 

2-77 

9.70 

9-95 

d 

24.2  24.3  24.4 

24.30 

24.80 

2.  12 

9  05 

9  30 

T 

24.0  24.5  23.9 

24-13 

25.00 

2.13 

9  05 

9  31 

D 

11.7   10.8  10.9 

11-13 

11.17 

0.40 

7-33 

7-58 

D 

II  .2    II  .2    II  .2 

ii  .20 

T 

26.2  25.3  26.1 

25-87 

d 

25-3  25-4  25-2 

25  30 

i 

31.0  31.0  31.0 

31  -00 

e 

28.7  28.3  28.6 

28.53 

c 

22.  I    21.8    21.0 

21.63 

C 

12.7    12.5    11.5 

12.23 

21    21 

21 

B 

10.0  10.8   10.7             10.50 

.... 

STELLAR   PHOTOMETRY. 
4-jm 


N 


PLATE   9. 


+20' 


I         •  • 


•-  ', 


•  .  .     • 


•  .     t 

*• 


•  +    10 


.  .     •  , 

«n        fffl 


0      a 

*.y 


(f)S 

.    Vv  .y 


• 

•    T 


o' 


• 


Scale,  i  mm=  13." 3. 


1902  November 


7220  S  CYGNI. 
R.  A.  2oh  3"  248.7.     Dec.  +57°  41'  52",  1900. 


CHAPTER    IX. — S   CYGNI. 


119 


TABLB  73. — 7220  S  CYGNI      PHOTOMETER  MEASURES  OF  COMPARISON  STARS. — Continued. 


1904  September  5.                                            6-INCH.                                       Good,  somewhat  dull. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

h    m 
ig  30 

O 

i? 
16 

Da, 

r 

4 

I 
e 
c 
C 
B 
B 
C 
c 
e 

ld 

13.8   14.3   14.9 
23.2  23.0  22.0 
24.0  23.0  23.5 
31  .1   30.8  30.8 
26.0  26.6  26.9 

20.0    19.9    2O.4 
13.2     12.5     13.3 
IO.3     IO.7     1O.2 

ii  .  i    10.  i    10.8 
'3-3   '3-2   12.  S 

2O.  7    21.5    21.2 
24.9    25.3    25.0 
31.4    31.9    31.8 
24.9    25.0    25.0 

14-33 
22-73 
23  50 
30.90 
26.50 
20.  10 
13.00 
10.40 
10.67 
13.10 
21.13 
25.07 
3«.7o 
24  97 

0.87 

2.OO 
2.06 
2.84 
2.22 
1.66 
0.65 
0.34 

7-83 
8.96 
9.02 
9.80 
'  9.  18 
8.62  . 
7.61 
7-30 

8.08 
9.21 
9.27 
10.05 

9-43 
8.87 
7.86 
7-55 

24.24 
3L30 
25  79 
20.62 
13  05 
io  54 

1904  October  I.                                                                                                                                      Good. 

21   33 
21   53 

21 
24 

D 
T 
d 

} 
e 
c 
C 
B 
B 
C 
c 
e 

d 
T 
D 

8.8     9.7     9.2 
23.9  23.9  24.8 
25.  i   26.2  25.8 

32  9  32.9  32.9 
26.8  27.7  27.  i 

21.6    21  .  I     21.2 
12.9    13.2     13.2 
II.  O    II.5    II.  I 

n  .8  11.7   11.7 

13-7    '3-4    13   0 
2O.  O    19.8    21  .0 
27.9    27.8    27.6 
31.3    32.2    31.9 
24.3    24.9    24.2 
22.8    23.1    23.6 
9.8      9.3      9.2 

9-23 

24.20 
25.70 
32.90 
27.20 
21.30 
13.  10 
ii  .20 
i'  -73 
13-37 
20.27 

27-77 
31.80 

24-47 
23-«7 
9-43 

9-33 
23.69 
25.09 
32.35 
27-49 
20.79 

13-24 
11.47 

O.  22 
2.OI 
2.14 
2.98 
2.40 

1.68 
0.67 
0-45 

7.10 

8.89 
9.02 
9.86 
9.28 
8.56 
7-55 
7-33 

7-35 
9.14 
9.27 

IO.  II 

9-53 
8.81 
7.80 
7-58 

1904  August  13.                                                 12-INCH.                                                               Good. 

17  48 
18  14 

26 
22 

c 
e 
t 

X 

T 
I 

V 

d 
o 
m 
m 
o 
d 
I 
T 

X 

} 
e 
c 

17.2   17.5   16.8 
25-5  26.3  26.4 
32.0  31.7  31.8 
53-5  54-6  54.2 
24.2  23.0  22.5 
38.2  39.0  38.6 
39.7  40.6  39.7 
22.5  23.9  23.  i 
43.8  44.7  45.0 
40.7  41.5  41.0 
40.9  41.1  40.7 
45.2  46.6  45.7 
23.4  23.1  21.9 
36.7  37-5  37-8 

22.  O    22.  I    2O.3 

53  5  55-o  53-9 
32.0  32.6  31.8 
27.9  28.2  28.  i 
18.6  18.2   17.2 

17.17 
26.07 
31-83 
54-io 
23.23 
38.60 
40.00 
23-17 
44-50 
41.07 
40.90 
45-82 
22.80 
37-33 
21-47 
54  «3 
32-13 
28.07 
18.00 

17-59 
27.07 
31-98 
54-12 
22.35 

37-97 

1.41 

2-37 
2.85 
5.16 
1.96 
3-55 
3-78 

2.  O2 

4-35 
3-88 

8.42 
9-38 
9.86 
12.17 

8.97 
10.56 
10.79 
9-03 
11.36 
10.89 

8.67 
9.63 

IO.  II 

12.42 
9.22 
10.81 
11.04 
9.28 
ii  .61 
ii  .  14 

22.99 

45-17 
40.99 

120 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABLE  73. — 7220  S  CYGNI.    PHOTOMETER  MEASURES  OF  COMPARISON  STARS. — Continued. 


1904  October  28.                                             12-INCH.                                                                   Good. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3 

Mean  of  6. 

H. 

P. 

k    m 

22       8 
22    30 

O 

24 
27 

m 

0 

d 
I 
T 

X 

} 
e 
c 
c 
e 
t 

X 

T 
I 
d 

0 

m 

30.3  30  9  30.8 
36.5  37.1   36.3 
12.9  14.1    13.3 
29.6  29.7  29.  i 
12.4   12.7   13.0 
41.7  41.4  41.6 

21.3    22.  7    21.8 

17.8  18.3  19.0 
12.5   ii  .8   12.  o 

II.5    II.4     12.  O 

18.0  18.3   18.2 

23.  I     22.8    23.3 

41.2  41.5  42.1 
14.0  14.2  13.7 
30.3  29.4  29.1 
14.7  15.3  15.2 
36.5  37.2  36.9 
31.8  31.7  30.9 

30.67 
36.63 
13  43 
29  47 
12.70 

4J.57 
21.93 

18.37 

12.  IO 
11.63 

18.  17 

23.07 

41  .60 

13.97 

29.60 

15.07 

36  87 

3i  47 

31-07 
36.75 
14-25 
29-54 
13-34 
41-59 
22.50 
18.27 
11.87 

2.76 
3  40 
0-95 
2.61 
0.83 
3  95 
1-97 
1.49 
0.64 

10.71 

"•35 
8.90 
10.56 
8.78 
ii  .90 
9.92 
9-44 
8-59 

10.96 
ii  .60 

9   '5 
10.81 
9  03 
12.  15 
10.  17 

9.69 
8.84 

1904  October  31.                                                                                                                  Good,  dull 

o  14 
o    37 

40 
43 

m 

0 

d 
I 
T 

X 

f 
e 
c 
c 
e 

i 

X 

T 
I 
d 

0 

m 

29.0  28.9  28.8 

35.2  34.2  34.7 

14.8   14.  I    14.0 
26.1   27.8   26.9 
12.2    12.  O    12.  I 

39  3  38-8  39.1 
20  .  o  20  .  3  20  .  o 
16.  i   16.2   16.8 
10.9  11.7   10.3 
10.7   10.8  10.2 
16.9  16.7  17.3 

21  .  I    20.3    2O.  2 

39  6  39.4  38.9 

12.2    13.7    13.0 
27.5    27.4    27.8 
14.9    13.9    12.9 

35-5  35.0  34.3 
28.0  28.6  28.1 

28.90 
34-70 

14.3° 
26.60 

12.  IO 
39-07 
2O.  IO 

16.37 
10.97 

10-57 
16.97 
20.53 
39.30 
12.97 

27-57 
13.90 

34-93 
28.23 

28.57 
34-82 
14.  10 
27.09 
12-54 
39-19 
20.32 
16.67 
10.77 

2.52 
3-'7 
0-94 
2.38 
0-75 
3  69 

1-74 
1.28 

0.53 

10.60 
11.25 
9.02 
10.46 
8.83 
11.77 
9.82 
9-36 
8.61 

10.85 
II  50 
9.27 

10.71 
9.08 

I  2.  O2 
IO.O7 
9.61 

8.86 

1000    August  30.                                    40-INCH   WEDGE  II.                                  Low,  seeing  poor. 

i  40 

2    2O 

y 

a 
X 
0 

m 

30.5  32  8  31.6 
46.5  50.5  48.3 
26.8  25.2  27.  i 

22.8    23.7    26.5 

18.0  20.7   18.4 

31-63 
48-43 
26.37 

24.33 
19.03 

3-05 
4.84 

2.43 
2.16 

i   35 

12.40 
14.19 
11.77 

11-51 
10.70 

12.65 
14.44 
12.03 
ii  .76 
10.95 

CHAPTER    IX. — S   CYGNI. 


121 


TABLE  73. — 7220  S  CYGNI.     PHOTOMETER  MEASURES  OF  COMPARISON  STARS. — Continued. 


1900   September  13.                             W-INCH,  WEDGE  n                                                     Good. 

Sidereal 
Time. 

Zen. 

Dist. 

Star. 

Scale  Readings. 

Wean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

h    m 

21    27 
22      6 

• 

m 
o 

a 

y 

•v 

/ 

X 
X 

/ 
y 

a 
O 

m 

15.7   17.0  14.9 

22.3    21.9    22  .4 
42.6    42.8    43.0 
30.9    31.0    31.8 
38.5    38.0   40.0 
15.8    14.0    14.2 
26.  I    24.2    25.2 
26.5    25.2    27.2 
15.  I     13.2    13.0 
28.2    31.8    30.9 
42.5    41.9    43.0 

21.9  20  .  5  21.4 

16.9    15.5    15.3 

15-87 

22.20 
42  .  80 
3I-23 
38.83 
14.67 

25-I7 
26.30 

13-77 
30.30 

42.47 
21  .27 

15-90 

15  89 
21.74 
42.64 
30  77 

0.82 

i-77 
4-23 
2-94 
3.80 

0.59 
2-33 

10.48 

"•43 
13  89 
12.60 
13-46 
10.25 
11.99 

10-73 
11.68 
14.14 

12.85 

13  7i 
10.50 

12    24 

14.22 
25-74 

1902    November  3.                                        WEDGE  v.            Poor,  occasionally  fair  for  a  moment. 

o  55 

n 
m 
0 
t 

a. 

y 

V 
X 

/ 
I 

X 

V 

y 

a 

t 

o 
m 
n 

31.8    32.9    33.6 
28.7    29.6    3O.2 
38.4    38.5    38.0 

49  5  49-3  50.0 
58.6  59.8  59.4 
41.3  41.8  42.3 
18.4  19.0  19.2 
38  .  2  40  .  3  40  .  i 
25.3  26.1   25.7 
26.3  26.9  26.3 
39  o  38.5  39.2 
18.6   19.0   19.8 
39.8  40.2   39.8 
56.8  59.8  59.7 
48.4  50.8  49.9 
36.2   35.8  36.3 
28.2  30.2   28.4 
36.9  36.2   36.2 

32.77 
29.50 
38.30 
49.60 

59-27 
41.80 

18.87 

39-53 
25  70 
26.50 
38.90 
19  13 
39-93 
58-77 
49.70 
36.10 
28.93 
36.43 

34.60 
29.22 
37.20 
49  65 
59  .02 
40.87 
19.00 

39-22 

26.  10 

3-iS 
2-57 
3-45 
4-77 
5-45 
3.86 

i   59 
3-69 
2.30 

it  .24 
10.66 

"   54 
12.86 

13  54 
"-95 
9.68 
11.78 
10.39 

11.49 
10.91 
11.79 
I3-" 
13-79 
12.20 

9-93 
12.03 
10.64 

1905    January  3.                                                                                                                             Good. 

i  35 

i  54 

54 

m 

0 
a 

9 
t 

v 

Y 
X 
X 

•y 

v 
e 

y 

a 
O 

14.8   15.8   15.3 

21  .4    22.4    22.4 

45-6  47.2  47.7 
32.9  31.7  30.7 
57-i   57-7  58-0 
58.1   58.4  58.0 
51.3  49.1  50.7 
24.2  25.1   25.3 
27.0  26.0  26.  7 
49.0  50.4  50.2 
58.5  59-8  58.4 
59-3  59-3  59-o 
28.4  30.1   29.3 
45.0  46.2  46.0 
23.1   23.7  24.0 
15.0  16.7   16.5 

15-30 
22.07 
46.50 

31-77 
57.60 
58.17 
5°-37 
24-87 
26.57 
49.87 
58.90 
59-20 
29.27 

45-73 
23.60 
16.07 

15.68 

22.84 

46.  12 
30.52 
58.40 

58.54 
50.12 

25-72 

I-I5 

2.01 

4-45 
2.76 
5-42 
5-43 
4.82 
2.27 

10.67 
11-53 
'3-97 
12.28 
14.94 
'4-95 
'4-34 
11.79 

10.92 
11.78 
14.22 
12-53 
I5-I9 
15.20 

14  59 
12.04 

122 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABLE  73. — 7220  S  CYGNI.     PHOTOMETBR  MEASURES  OF  COMPARISON  STARS. — Continued. 


1905    November  18.                               40-INCH,  WEDGE  V.                                                        Good. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

h    in 

6  30 

X 

19.3  20.  i   20.  o 

19.80 

19  25 

1.62 

ii   95 

12  .  2O 

V 

42.0  42.8  44.2 

43.00 

42  .  10 

4.01 

14.34 

14-59 

S 

54-i  56.6  53.1 

54.60 

54.04 

5   15 

15-48 

15.73 

V 

21  .0  20.  7  20.  7 

20.80 

20.86 

i  .80 

12.13 

12.38 

a 

40  .  5  40  .  i  40  .  i 

40.43 

39.76 

3  75 

14.08 

14-33 

O 

15   5    '5-9   15  8 

15.73 

15-36 

!.I6 

"   49 

II  .74 

t 

33  -6  32.1   32  .8 

32.83 

32-46 

2.90 

13-23 

I3.48 

t 

•32     I     "?2    O    ^2    2 

32    IO 

0 

14  o  15.7   15.3 

I  S   OO 

l6    8    41    3    3O.8 

v 

20  8  20.9   21    i 

2O   Q3 

1 

52.  i  53.  7   V4..6 

c-i    47 

Y 

6  50 

X 

18.7   18.3   19.1 

18.70 

TABLE  74.— 7220  S  CYGNI.    CONSTANTS  FOR  REDUCTION  AND  COMPARISON  WITH  CATALOGUE  MAGNITUDES. 


6-INCH. 

Star. 

1904  September  3. 

1904  September  5. 

1904  October   i. 

C. 

Obs.  Mag. 

JMag. 

C. 

Obs. 

Mag. 

J  Mag. 

C. 

Obs.  Mag. 

4  Mag. 

H. 

P. 

H.        P. 

H. 

P. 

H. 

P. 

H. 

P. 

H. 

P. 

B 
C 
D 

Means 

Mo... 

0.30 
0.51 
0.40 

7-23 
7-44 
7-33 

7.48 
7.69 
7.58 

+  .15   +  .01 

-  .44  -  .27 
+  .29  +  .26 

0-34 
0.65 

O.  12 

7-30 
7.61 
7.08 

7-55 
7.86 

7-33 

+  .22 

-•27 
+  .04 

+  .08 
—  .  10 

+  .  01 

0-45 
0.67 

O.22 

7-33 
7-55 
7.10 

7.58 
7.80 
7-35 

+  •25 
-•33 
4-  .06 

+  .11 
-  .16 
+  -03 

0.40 

7-33 
6-93 

7.58 
7.18 

±.29   ±.18 

o.37 

7-33 
6.96 

7.58 

7-21 

±.18 

±.06 

0-45 

7-33 
6.88 

7-58 
7-13 

±.2I 

±.IO 

12-INCH. 

40-INCH 

Star. 

Mag. 
6-inch. 

c. 

Star. 

Mag. 
12-inch. 

C. 

Aug.  13. 

Oct.  28. 

Oct.  31. 

Nov.  3. 

Jan.3. 

Aug.  30. 

Sept.  13. 

c  

8.60 
9  03 
9.26 

9-79 
8.97 

1-41 

2.  O2 

2-37 
2.85 
I  .96 

0.64 

0-95 
1.49 

1-97 
0.83 

o.53 
0.94 
1.28 
i-74 
0-75 

i 

.  n 

0 

X 

ft 
M 

> 

10-53 
10-73 
11.32 
"•95 

o  59 
0.82 

1-77 
2-33 

d  

2-57 
3-45 
3-69 

i.i5 

2.OI 

2.27 

1-35 
2.16 

2  43 

e  

/  

T  

can  C 
eanM 

' 

Mean  C  .  .  . 

2.  12 

9-13 

7.01 

i.iB 

9-13 
7-95 

1.05 

9-13 
8.08 

3-24 
"•33 
8.09 

I.  8l 

11-33 
9-52 

1.98 
ii   33 
9  35 

i-47 
11-13 
9.66 

Mean  Mag. 
M0  . 

9   '3 

ag. 

ii 

•13 

CHAPTER    IX. — S   CYGNI. 


123 


16  IS  I*  13 


MAGNITUDE 
if  II 


7ZZO  S  CYGNI 


£20  • 
fe 


FIG.  25. — MAGNITUDE-CURVE  FOR  S  CYGNI. 


124 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABLE  75. — 7220  S  CYGNI.     MBAN  MAGNITUDES  OF  COMPARISON  STARS. 


6-INCH. 

Star. 

September  3. 

September  5. 

October 

i. 

Mean. 

Mag. 

JMag. 

Mag. 

J  Mag. 

Mag. 

J 

Mag. 

Mag.  H 

Mag.  P 

A  Mag. 

B 
C 
D 

c 
d 
e 

T 

7-23 
7-44 
7-33 

Mean  . 

8.62 
9-05 
9-32 
9.70 
9.06 

Mean  . 

—  0.06 
—  0.09 

+  0.16 

7-30 
7.61 
7.08 

+  O.OI 

+  0.08 
—  0.09 

7-33 
7-55 
7.10 

+  0.04 

+  O.02 
—  O.O7 

7.29 
7-53 
7-"7 

7-54 
7-78 
7.42 

±0.04 
±0.06 

±0.  II 

7-33 

7-58 

±0.07 

+  O.O2 
+  O.O2 
+  O.O6 
—  O.O9 
+  0.09 

8.62 
9.02 
9.18 
9.80 
8.96 

+  O.O2 
—  O.OI 
-0.08 
+  O.OI 
—  O.OI 

8.56 
9.02 
9.28 
9.86 
8.89 

—  0.04 
—  O.OI 
+  O.O2 
+  O.O7 
-0.08 

8.60 

9-03 
9.26 

9-79 
8.97 

8.85 
9.28 
9-51 
10.04 
9.22 

±0.03 
±0.01 
±0.05 
±0.06 
±0.06 

9.13 

9.38 

±0.04 

12-INCH. 

Star. 

August  13. 

October  28. 

October  31. 

Mean. 

Mag. 

4  Mag. 

Mag. 

JMag. 

Mag. 

J  Mag. 

Mag.  H. 

Mag.  P. 

d  Mag. 

c 
d 
e 

T 

I 
m 
o 
•x 

8.42 
9-03 
9-38 
9.86 
8.97 

Mean  . 

10.56 
10.89 
11.36 

12.  17 

Mean  . 

—  O.  12 
+  0.05 
—  O.OI 
—  O.OI 
+  O.  II 

8-59 
8.90 

9-44 
9.92 

8.78 

+  0.05 
-0.08 
+  0.05 
+  0.05 
-0.08 

8.61 
9.02 
9-36 
9.82 
8.83 

+  0.07 
+  0.04 
-0.03 
—  0.05 
-0.03 

8.54 
8.98 

9-39 
9.87 
8.86 

8.79 

9-23 
9.64 

IO.  12 
9.II 

±0.08 
±0.06 
±0.03 
±0.04 
±0.07 

9.13 

9-38 

±0.06 

+0.03 
+  0.16 
+  0.04 

+  O.22 

10.56 
10.71 

"•35 
ii  .90 

+0.03 

—  O.O2 

+0.03 
—0.05 

10.46 
10.60 
11.25 
"•77 

—  0.07 
-0.13 
—  0.07 
—  0.18 

!0.73 
".32 
"•95 

10.78 
10.98 

"•57 

1  2.  2O 

±0.04 

±O.  10 

±0.05 
±0.15 

11.13 

"•38 

±0.08 

40-INCH. 

^       August   30. 

September  13.    November  3 

January  3. 

Mean. 

w      Mag. 

J  Mag. 

Mag. 

^  Mag.  Mag. 

J  Mag.>  Mag. 

JMag 

.  Mag.  H 

.  Mag.  P. 

A  Mag. 

I       . 

10.25 

10.48 

"•43 
11.99 

—  0.07    10.39 
—  0.15    10.66 
-0.07    11.54 
4-o.i6    11.78 

+  0.07 
+  0.03 
+  0.04 
-0.05 

10.32 

^  10.63 

3    i  i  .  50 

^  "-83 

10.57 
10.88 

"•75 
12.08 

±0.07 
±0.07 
±0.04 
±0.08 

m      10.70 
o       11.51 
x       "-77 

Mean. 

+  0.07 

+  O.OI 

—  0.06 

10.67 

"•53 
11.79 

+  O.O 

+  0.0 

—  o.o 

11.07 

11.32 

±0.06 

y      12.40 
a      14.19 

t       

+  0.09 
+  0.29 

12.60 
13.89 

+  0.29    11.95 
—  o.oi    13.54 
....     1  2  86 

-0.36 
-0.36 

12.28 
13.97 

-0.0 
+  0.0 

3    12.31 

i  13-90 
(12.86 
(14.94 
(14.34 

12.56 
H-I5 
13  " 
15-19 
14-59 

±0.19 
±0.18 

0        

r     

Also  3,  1905  November  18,  15.48  and  15.73. 


CHAPTER   IX. 


CYGNI. 


125 


TABLE  76. —  7220  S  CYGNI.      VISUAL  OBSERVATIONS  OP  THE  VARIABLE. 


No. 

Date. 

h 

Aperture. 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing. 

I. 

J  Mag. 

Month 
and  Day. 

Hour 
C.  S.  T. 

Julian 
Day 
G.  M.  T. 

Steps. 

Mag. 

i 

2 

3 
4 

5 

6 

7 
8 

9 

IO 

1  1 

12 
13 

'4 
15 

16 

18 

'9 
20 

21 
22 
23 
24 
25 
26 

27 
28 

29 
30 

3' 
32 
33 
34 
35 
36 
37 
38 
39 
40 
4« 
42 
43 

1892 
Dec.    14 

1893 
Jan.      7 
July     2 
3 

Aug.     3 

ii 

17 
Sept.    4 
6 

13 
26 
Oct.      4 

IO 

21 
29 

Nov.     3 
6 

9 

H 

16 
20 

25 
29 
Dec.      i 
3 
5 
8 

12 

17 
28 

1894 

Jan.    10 
June    6 
20 

24 
28 
July     2 
8 
23 
29 
Aug.     6 
8 
18 
20 

9 

7 
:o 

10 

9 
9 

10 

8 

9 

8 
8 
8 

8 

7 
6 

7 
8 

6 

8 

7 
7 
6 
6 
8 

7 
6 
6 
6 

7 
7 

7 

10 
10 
IO 
IO 
IO 

9 

IO 

9 
9 
9 
9 
9 

2410000+ 

2471-52 

2647.67 
2648.67 

2679.63 

2683.61 
2689.66 
2711.58 
2713.60 
2720.58 
2733-58 
2741.56 

2737-56^ 

2758-52 
2766.50 

2771-51 
2774.60 

r 
i 

2777-52  < 

I 
2782.56 
2784.54 
2788.54 
2793-50 
2797  5' 
2799  58 
2801.54 
2803.51 
2806  .  50 
2810.49 
2815.55 
2826.54 

2839.52 
2986.67 
3000.67 
3004  67 
3008.67 
3012.67 
3018.63 
3033-67 
3039-63 
3047-63 
3049.63 

3059-63 
3061.63 

60 

150 
150 
150 
150 
150 
40 

40 

150 

40 
150 
150 
150 

40 
150 

IO 

150 
150 
150 
150 
150 
150 
150 
150 
150 
150 
150 

150 
150 
150 
150 
150 
150 

150 

150 
150 
150 
'50 

6 

6 

6 
6 

6 

6 
6 
6 
6 
6 
6 
6 

6 

6 

6 
6 
6 
6 

6 

6 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

9-5 

1  1.  06 
>"-5 

<n-5 

ii  .92 

11.89 
11.80 
11-52 
11.27 

10.63 

10.03 
10.  14 
10.23 
10.19 

10.  19 

10.40 

10.30 
10.46 
10.60 

10.70 
10.65 
10.66 
10.88 
11.08 

II.  IO 

11.27 
ii  95 

<I2.0 
<I2.0 
<I2.3 
12.38 
12.48 
<I2.3 

12.35 

12.46 

12.  IO 
II    51 

11.13 
II  .05 

poor 
good 

o 

24 
200 

2OI 

-0.74 
+0.31 

fm4i>,  2J2/,  limit  p  ^ 

23-9 

<22 

<22 

<22 

<22 
<2O 
19.2 
19.4 
19.9 
21-3 
23-8 

26.7 

30-4 
29.8 
29.1 
29-4 

29-4 

|  28.2 
28.8 

27-7 
26.8 
26.2 
26.5 
26.4 
25-2 
23-9 
23-8 
22.8 
19.0 

16.5 
16.0 
<i7.o 
16.7 
16.2 
18.2 
21.3 

20.8 

23  6 
24.1 

\nirn,  dse,  erf,  gif,  j^h.  .) 

21  .  i,  27.7  

i>  not  seen  />  easy 

-  iinot  seen,  036,  62c,cid,d2e  > 
(.120,  p  not  seen,  mandm=/) 

^  not  seen,  />easy,  <?  glimpsed 

IO  1.  IO  O.  . 

fair 

fine 

good 
good 
good 
fine 

fair 

fair 

moon 
moon 
fair 
good 
poor 
fine 
fine 
good 
good 
good 
fair 

fair 
good 
fine 
good 
good 
good 
good 
fair 
good 
good 
fair 
fair 
fair 

264 
266 

273 
286 

294 
300 

3H 
319 
324 
O 

3 
8 

IO 

14 
19 
23 
25 
27 
29 
32 
36 

52 

230 

234 

244 
259 
265 
273 
275 
285 
287. 

+0.19 
+  0.19 
+  0.28 
+  0.36 
+  0.31 

—  O.O2 

-0.28 
-0.08 
+  O.OI 

-0.05 
—  0.09 

+0.07 

-0.07 
o.oo 
o.oo 

—  O.O2 
-0.15 
—  O.2I 
—  0.05 
+  0.03 

—  o.  19 

-0.25 

—  o.  14 

—  o.  19 
+0.03 

4-0.18 
+0.63 
+0.39 

—  O.O2 

4-o.  ii 

—  0.12 
4-0.14 

£21*,  m;  

p2V,  TllX  
Tip,  OIV,  T12X  

vjp,  Im,  hp,  o  not  seen.  .  .. 
(  g2/  /3/i  hk  ^1 

19.8,  19.0  
19.8,  20.  o  

21.8,  21  .O,  21.0  
22.8,  24.7  

26.  2,  27.7,  26.  I  
3O.  I,  3O.6  

"1046,  by,  C2d,  d2e,e^f,eig 
(n2o,  pn,  p4~5q,  limit  q.  .  r 
-  /3&,  hik,  k2l,  l2m,  myi.  . 
(vl,  or  vil,  kiv,  ii2m  ....  j 

i  '  V2fo 

29.  I,  3O.6  

27  6,  30.6  

(046,  bic,  C2d,d2e,  e\],g\\,  ~\ 
-  J4h,  hik,  hk,  kym,  m2n, 
(»20,  oip,  limit  p  

28.1,  30.6  
29.1,  29.6,  30.7,28.2 

28.6,  28.7,  29.  I,  27.2 
29.1,  27.6,  28.7,  26.7 
28.  I,  29.6,  29.7,  27.7 

26  7,  28  7  27  6 

(poor  pio,  O2q,  limit  q,  r  } 
-.  not  seen  

(.jyo,  Vlh,  V2k,V2~3l  

036,  b2c,cid,  dje,  limit  e.J 
\nh  or  ilk,  }yv,  iii—2l  .  . 

\fyv,  km,  ilk,  ml  

f^V  Vlfl  Tllk,  V2l 

25.7,  27.  7,  26.6,  27.1 
25.  7,  26.7,  26.  i,  26.  i 
25.7,  27.7,  26.1  
25.2,  27.7,  26.6,  26.  i 

24.  2,  26  I  .. 

Vl  k2V  h2—yV  V2m 

vl,  kiv,  V2m  
lo-iv,  km,  h2v,  i>2m  

liv,  mm,  1130,  limit  1-2  <  q 
l2—yv  mm  V3o  

23-7,  23.1,  25.0.  .  .  . 
23  .  2,  23  .  I,  25  .O  .... 

13—411,  mi—  2v,  vi—  20  

22.2,  22.6,  23.5  

11  not  seen  limit  x 

11  not  seen  limit  2  <C  x 

v  not  held,  limit  2  <  x,  X2y 
X2ii,  vy,  uncertain  
xiv,  yiv,  limit  v  
xo-m,  m-2y  

l$V,  V2X  

hv,  vi-20  

I7.O,  16.4  
17-0,  15-4  
18.5,  17.9  
21.2,  21.5  

20.  7,  21  .0  .  .  . 

23-7,  23.5  
21.7.  24.  S.  . 

126 


RESEARCHES   IN   STELLAR    PHOTOMETRY. 


TABLE  76. —  7220  S  CYGNI.    VISUAL  OBSERVATIONS  OF  THE  VARIABLE. — Continued. 


No. 

Date. 

Ocular. 

£ 

V 

3 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing. 

(, 

A  Mag. 

Month 
and  Day. 

Hour 
C.  S.  T. 

Julian 
Day, 
G.  M.  T. 

Steps. 

Mag. 

44 
45 
46 

47 
48 

49 
50 
5i 

52 

53 

54 
55 
56 

57 
58 

59 
60 
61 
62 

63 
64 
65 

66 

6? 
68 
69 
70 
7i 
72 
73 
74 
75 

76 

77 
78 

79 

80 
81 
82 
83 
84 

1895 
June     (. 

13 
20 

1898 
June  25 
July     6 

25 
Aug.     8 
20 

1900 
June  28 

July  20 
Aug.  1  6 
29 
3o 
Sept.  12 

12 

13 
13 
Oct.      4 

9 
9 
9 

ii 

10 

ii 

IO 

9 

12 
IO 

f 

» 
[- 

IO 

6 
6 

16 

10 

2410000  + 

3349-63 
3358.63 

3365-63 

4466.71 
4477.67 

1496.  7  i 

4510.67 
4522.63 

5199 

5221.75 
5248.67 
5261 
5262 

5275 
5276.67 
5297-67 
5309-67 

5319-50 
5345-5° 

5666 

5824.92 
6052.67 

150 
150 
150 

80 
275 
275 

275 
275 

237 

237 
460 

6 
6 
6 

12 
12 

12 

12 
12 

40 

40 
40 

v  glimpsed,  vx  

19.0 
23.6 

24-5 

15-4 
14.4 

8.4 
8.4 
<i3 

7-8 
4-9 

<     0 

3-0 
<   9 

<I5 

IO.2 
17.0 
17.0 

17-8 
21  .O 

25-7 

4-4 
27.9 

"•95 

II  .  12 
10-97 

12-57 
12-75 
13.90 

13.90 
<i3-o 

14.02 

14.60 
<I5  6 
14.99 
<'3-9 

<I2.7 

13-52 
12.30 
12.30 

12.  18 

i'  -59 
10.79 

14.68 
10.37 
10.32 

good 
good 
good 

poor 
good 

good 
fair 

fine 
fair 

poor 
moon 

good 
fair 
fair 

fine 
fair 

good 

poor 
fair 
good 

248 

257 
264 

57 
68 

87 

101 

•36 
158 
207 

213 

234 
246 

253 
282 

276 

107 
8 
9 

—  O.  II 

-0.75 

-0.78 

+  0.24 
-0.13 

+  o.  19 

—  0.21 
-0.51 

+  o.  15 

+  I.I9 

+  0.23 
-0.13 
+  O.2I 

+  0.23 
+  0.24 

—  O.70 

+  0.46 
+  O.O4 
—  O.O4 

V<\X,  ll—2V  
TJ^—  6#  

23.0,  24.2  

%4y,  yiv,  u'2y    

y2-v,  limit  v  

/  y&v  limit  i  <v  ....          ) 

1  angle  ydv  is  a  right  angle  j 
y8v,  limit  v  

v  not  seen,  limit  3-4  <  y.  . 

{yiav,  P$y,  via.,  viy  | 
d  is  1  6  magnitude,  £  is  > 
17  magnitude.               ) 
yja,  14-51;,  limit  v  

6.4,  7.9,  10.4,  6.7.  . 

d  (is  it  <5  or  v)  limit  

05-61),  02-3,5,  TJO-I-D  
•v  is  <  «  

2.8,  2.0,  4.3  

75 

237 
237 
460 

150 
«5° 

237 
75 

12 

40 
40 
40 

6 
6 

12 

40 

12 

(photometer  ) 

-'•v  not  seen,  limit  4  <  x,  • 
(     y  glimpsed  .                    ) 

"•4,  9-4,  9-8  
15-5,  18.4  
17.4,  16.5  

ys-v,  vo.vs1*  (t  =  «±)  

*3-4i>,  V2y  

jviy,  X2-yi,  yil,  <»6Y,  i\&,\ 
(     limit  d.                          i1 
(047),  xiv,  viy,  limit  y.  .  .) 
-.  /is  i  ith  mag.  or  brighter,  >• 

(y  is  ni«..  .  .            ) 

16 

26 
Nov.  21 

1901 
Oct.    1  8 

1902 
Mar.   15 
Oct.    29 

3° 
3i 
Nov.    3 

'9 
24 
Dec.   26 

1903 
Tan.    17 
Mar.  20 
Apr.     3 

1904' 
July   27 

31 
Aug.  27 
Sept.    3 
Oct.      i 
8 

18.0,  18.0,  17.4  

m^v,  oiv,  v$x  

vl  

• 

ayv,  v6  

J21I,  Vl  

photometer  

9 
9 

8 

9 

7 

6 
17 
'4 

10 
12 

8 

IO 

9 
9 

6053.67 
6054.63 
6056.63 
6072.58 
6077.63 
6110.54 

6132.50 
6194.96 
6208  .  83 

6689.67 
6695.75 
6720.58 
6727.67 
6755-63 
6762.63 

75 
237 
237 
75 

237 

460 
237 
237 

12 
40 
40 
12 

24 
40 

40 
40 
40 

24 

photometer  

«2y,  i  near  limit  

photometer  

9.68 
11.03 

»i  9 

12.70 

13-50 
<*3-8 

<i5  6 

10.5 

10.  16 

ii-3° 
11.71 

<I2.O 

'3  32 

poo» 
good 
good 

fair 

12 

28 

33 
66 

88 

-0.72 
+  0.13 

—  O.  IO 

-0,27 

photometer  

photograph  

yi-2v,  1141  

y8v,  tiv,  V2*,  v6-Sy  
v  not  seen,  limit  *  

14-9,  '4  6  
8.4,  9.6,    11.4,    12.7 

14  * 

10.5 
<   9 

<    0 

•v  not  seen,  limit  #,  y  ;and  ff 
seen. 

photograph  

fair 
good 
good 
good 
good 
fair 

322 

22 
29 

64 

—  0.06 
-4-0.61 
+0.80 

+  0.62 

•v&l  

29.7 
22.4 

2O.  2 

<I9 
"•5 

40 
40 
237 

6 
6 
do 

m6v,  via,  v6x    

01-2V,  T1IX  

v  not  seen,  x  seen  

18.1,  23.0,  25  .0  

2O.5,    20.  O  

ysv,  vit  

11.4,  1  1.  6  

CHAPTER   IX. — S  CYGNI. 


127 


TABLE  76. — 7220  S  CYGNI.    VISUAL  OBSERVATIONS  OF  THE  VARIABLE. — Continued. 


No. 

Date. 

Ocular. 

Aperture. 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing. 

t. 

J  Mag. 

Month 
and  Day. 

Hour 
C.S.T. 

Julian 
Day 
G.  M.  T. 

Steps. 

Mag. 

85 
86 

8? 
88 
89 
90 

92 
93 
94 
95 
96 
97 
98 

99 

100 
101 

1  02 
103 
104 
105 
1  06 

1904 
Oct.   ;8 
Nov.    6 

1905 
Jan.      3 

3 
24 
28 
Feb.    14 
Mar.  24 
Apr.     4 
30 
May   31 
June  22 
July   26 
Aug.     9 
20 

22 

Sept.    2 
19 
Oct.      i 

21 

Nov.  1  8 
Dec.  30 

ii 

6 

7 
6 

7 
16 

.  17 
16 

15 
9 
9 
9 
9 
9 
9 
ii 
7 
10 

9 
6 
6 

2410000+ 
6782 
6791.71 

6849.50 
6849.54 
6870.50 
6874.52 
6891  .92 
6929.95 
6940  .  92 
6966  .  8$ 

6977.63 
7019.63 
7053-63 
7067.63 
7078.62 
7080.63 
7091.71 
7108.54 
7120.67 
7140.63 
7168.51 
7210.51 

67 

237 

237 
237 
450 
450 
250 
150 
237 
237 
150 
150 
ISO 
150 
237 
237 
237 
237 
750 
750 
450 
750 

12 

40 

40 
40 
40 
40 
40 
6 
40 
40 
6 
6 
6 
6 
40 
40 
40 
40 
40 
40 
40 
40 

i)  not  seen   limit  y      

<i6-4 
6-5 

2.6 

<   6 
8.7 
ii  .  i 

19  5 
18.8 
20.5 

30.5 
25.6 

2O.  2 
17.0 

ii.  8 
13.0 
8.0 

7.0 

<   5-7 

I  .2 

-   6.0 
7-9 

<I2.4 

14.29 

15.00 

<i4-4 
13-87 
13-39 
11.85 
ii   98 
11.66 

10.00 

10.80 
11.72 
12.30 
13.28 
13.01 

13-97 
14.  16 

i5  30 
16.5 
14.00 

good 
fair 

good 

dull 
good 
good 
haze 

good 
fair 
good 
fair 
good 
poor 
good 
good 
good 
poor 
good 
good 
good 

93 

151 

i76 
193 
245 
256 
282 
313 
9 
43 
57 
68 
70 
81 
98 

130 
158 
200 

+  0.34 

+  0.49 

—  0.28 
—  0.41 
-0.32 
+  0.03 
+0.26 
-0.25 
+0.50 
+  0.23 
+  0.29 

+  0.77 
+  0.36 
+  0.87 
+  0.46 

+  0.68 

+  2.0 
+  0.10 

7.4.  6.7.  5.  S.  -  . 

a8l),  D3«,  D3<5  

i-4,  3-3,  2.5  > 

f  not  seen   o.  glim  psed  .    . 

tS>—iov,  173—  4a,  v6t  
yb—jv  vi  1    

6.  i,  11.4,  8.7  
9.  o.  1  1  6  .  . 

03-41;,  vix  

19.0,  20.  o  
17.0,  19  .0,  20.4  
20  s  (16  6) 

vl,  -vim,  -v$n  

02-37J,  V2X  

X3-4V,  TJ2-3y  

x8-i<yv,  yyv,  v^t  
£4-51;,  t/6y,  1*80    

25.7,  25.1,  26.6  

19-5,  21.0  

15-5,  18.4  
10.9,  12.6  
10.  o,  13.4,  14.6  
6.1,  11.7,  8.3  

c  6  7.7.. 

y6—  8i>,  &vt  v^-d  i  
£5—  6i>  

-i-3,  0.3,  3.5  

5-5,  9-2  

128 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


•o 

01 


jf      9 


•n 
o 
n 


II 

1 


si 

m  f) 


o 
o 


.   36  — LiGHT-ClJRVB  OP  S  CVGNI. 


CHAPTER    IX. — S  CYGNI. 
TABLE  77. — 7220  S  CYGNI.     MEAN  MAGNITUDES  FROM  27^  DAY  GROUPS. 


129 


Group  No  .... 
T  D  .  . 

i 

2 

3 
82 

4 

5 
nfi 

6 

ii',: 

7 

8 

9 

IO 

II 

12 
ttf\ 

2ll 

244 

272 

299 

326 

r         ' 

12 

26s 

284. 

..._]        M 

10.28 

2447          JM 

—  0.18 

—  o  08 

L    No. 

2 

•3 

r      t 

'4 

18 

28l 

•,-,-,-,  )     M 

10.44 

I  I  .  13 

2"3  j      JM 

—  O.OI 

—  O.O2 

—  o  08 

L     No. 

8 

6 

•J 

r     < 

„  J         M 

3°99  j       JM 

L     No. 

r     * 

70 

IOI 

M 

12.66 

1  1  .  OO 

4402  1      JM 

+  O.  IO 

+  0.08 

L     No. 

2 

2 

f         < 

167 

?cft 

M 

5054  i       JM 

—  o  87 

—  O    t7 

L     No. 

r     < 

118 

286 

e,,fi  J     M 

14.68 

IO    7O 

5716  1      JM 

-f-O.  17 

o  56 

L     No. 

I 

I 

r    * 

22 

40 

78 

90 

fin™  J           M 

IO.2I 

II  .03 

I2.7O 

13.50 

JM 

—  0.40 

—  0.26 

—  0.28 

+  0.07 

L     No. 

3 

I 

I 

I 

r     < 

5 

40 

92 

1(,S 

108 

firs,  J         M 

10.  16 

II  .  50 

13.80 

I  $    OO 

i  "*  6"* 

6684  ^j      JM 

—  O.  11 

+  o.  24 

4-o    12 

O   OO 

L     No. 

I 

2 

2 

r     < 

„  j         M 

'°'°  i      JM  . 

I    No.  ' 

r     t 

Means]     ^ 
L    No. 

15 
10  35 
-0.13 

H 

39 
1  1  .  20 

+  O.OI 

9 

80 

13.13 
+  O.  II 

5 

94 
13-77 
+  0.08 

3 

118 
14.68 

+  0-37 

i 

H5 
14.02 
—  0.87 
I 

1  66 

14.80 
-0.18 

2 

198 
13-63 
-0.44 

2 

232 

12.67 
+0.14 

4 

259 

II  .92 

+  O.O2 
IO 

284 
11.36 
+  0.06 

9 

314 
10.26 
-0.08 

4 

130 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABLE  78 — 7220  S  CYGNI.     OBSERVED  MAXIMA  AND  MINIMA. 

Elements  of  maximum.     1893  October  28  (J.  D.  2412765)  +  32<!d  (E  — 32).     M  —  m=  162*. 


MAXIMA. 

MINIMA. 

ji 

8 
o, 
W 

Date. 

Mag. 

Corr. 

Wt. 

I 

w 

Date. 

Mag. 

Corr. 

Wt. 

Calendar. 

J.D. 

H. 

P. 

Calendar. 

J.D. 

H. 

P. 

32 
33 
34 
37 
40 

4i 
42 
44 
45 

1893  Oct.  26 
1894  Sept.  20 

'895  J"ly  25 
1898  Apr.  16 
1900  Dec.  27 
1901  Nov.    i 
1902  Oct.   17 
1904  July  1  8 
1905  May  29 

2763 
3092 
3400 
4396 
538i 
5690 
6040 
6680 
6995 

10.  10 

10.35 
me 
tnc 
me 
me 
10.6 
10.5 
10.3 
10.31 

—  2 

+  i 

-'7 
+  i 
+  8 
-  9 
+  15 
+  3 
+  8 

33 
5 

2 
I 

6 

r 
4 
4 

12 

32 

33 
34 
38 
40 
42 
43 
45 
46 

1893  May  19 
1894  Apr.     6 
1895  Feb.  15 
1898  Sept.  25 
1900  July  29 
1902  Apr.  20 
1903  Mar.  26 
1904  Dec.  25 
1905  Nov.  1  8 

2603 
2925 
3240 
4558 
5230 
5860 
6200 
6840 
7168 

15.6 

15-2 
16.5 

me 
me 
me 
me 
me 
me 
15.8 

15-4 
16.8 

o 
-  4 
-'5 

—  i 

+  19 
-  3 

+  13 

4-  i 
+  3 

i 

2 

I 

4 
8 
i 
4 
'3 
8 

10.4 

IO.2 
IO.O 

10.06 

TABLE  79. — COMPARISON  OP  PHOTOMETRIC  MAGNITUDES. 


Star. 

H.  C.  O. 
Vol.  37- 

H.  M. 
Park- 
hurst. 

J.  A.  Parkhurst. 

Star. 

H.  C.  O. 

Vol.  37. 

H.  M. 
Park- 
hurst. 

J.  A.   Parkhurst. 

H. 

P. 

H. 

P. 

a 
c 
d 
e 

I 

7.78 
8.76 
9.18 
9  43 

7  93 
8  99 
9-25 
9.66 
10.27 

7-53 

8.54 
8.98 

9  39 
9.87 

7.78 
8.79 
9  23 
9.64 

IO.  12 

/ 
m 
o 

X 

y 

ii  .  19 

10.53 
10.73 
11.32 

11-95 
12.31 

10.78 
10.98 
"•57 

12.  2O 
12.56 

ii  .62 

12.  14 
I2.9O 

13-48 

UJ 
Q 


sa° 

too 

OAY3 
ZOO 

300 

+OO 

~  A- 

T 

± 

\ 

e  a  _ 

ZQ&CYC. 

<Nl 

\ 

:  :  :  :   7£ 

1  1         C 

I              \ 

.?x.» 
in.  - 

I60<* 

V 

!  / 

r 

'         1 

M 

3 

_  [ 

1  1 

i 

1  

V 

L 

r 

/^ 

/ 

'".    \ 

-.__._  

A_ 

\ 

\  _  — 

u 

1 

t 

.-i. 

5    

.  -L. 

] 

_  _  L_  , 

_      I      -_ 

f 

f 

.. 

f-- 

\  

f  : 

n 



f-- 

W  

f- 

_  _      _      \ 

-  _i 

r 

1 

"  ~? 

j 

IS  

i 

FIG.  27. — MEAN  LIGHT-CURVE  OF  S  CYGNI. 


CHAPTKR   IX. — S   CYGNI.  131 

The  mean  light -curve  was  derived  from  observations  as  far  as  1905  March 
24.  It  shows  a  steady  and  rapid  decline,  with  a  well-defined  minimum,  a  halt 
in  the  rise  at  about  i2th  magnitude,  and  a  maximum  about  as  sharp  as  the  mini- 
mum. The  halt  in  the  rise  is  referred  to  by  Townley  as  a  double  maximum, 
but  nothing  is  shown  of  it  in  the  mean  light-curve  published  in  the  Harvard 
Annals  87,  Plate  in.  In  the  light-curve,  fig.  26,  this  halt  is  shown  before  the 
maxima  of  epochs  32,  33,  34,  40,  and  45.  At  the  other  maxima  the  observations 
are  too  few  to  furnish  evidence. 

LATER  NOTE. — It  was  possible  to  observe  the  minimum,  epoch  46,  in  the 
fall  of  1905,  in  better  conditions  than  any  previous  one.  Advantage  was  taken 
of  an  unusually  clear  night,  November  18,  to  secure  photometer  measures  of  the 
faint  comparison  star  S  with  the  result,  15.48  and  15.73,  on  the  Harvard  and 
Potsdam  scales,  respectively.  The  variable  was  then  i6£  (corresponding  to  i6| 
on  the  Potsdam  scale),  the  faintest  ever  observed. 

The  difference  in  scale  is  very  noticeable  in  Table  79;  as  compared  with 
mine,  the  Harvard  and  H.  M.  Parkhurst  scales  are  respectively  15  and  16 
per  cent  more  extended.  The  reasons  for  this  discordance  are  not  clear,  but 
it  should  be  noted  that  the  measures  of  the  faint  stars  in  the  Harvard  list  all 
depend  on  the  single  star  a  ( =  C  of  Table  70,  color  GW) ,  too  slender  a  basis 
it  would  seem,  especially  as  the  meridian  photometer  measures  in  Volume  44 
of  the  Annals  depend  on  three  zones,  one  of  which  was  interrupted  and  the  other 
two  stopped  by  clouds.  It  may  also  be  said  that  the  stars  x  and  y  were  used 
with  the  6-inch,  which  would  make  the  limit  of  that  instrument  about  13.7  if 
the  Harvard  scale  is  accepted.  Taking  everything  into  account,  it  seems  probable 
that  the  truth  lies  between  the  two  scales. 


CHAPTER  X. 


7269  SX  CYGNI. 
R.  A.  20*1  urn  33s.2|  Dec.   +30°  45'  58"  (1900). 

This  variable  was  discovered  by  Anderson  in  1899  and  observations  began 
in  October  of  that  year,  measurements  being  made  of  the  place  of  the  variable 
and  the  brighter  comparison  stars  with  the  6-inch.  The  place  given  above  was 
derived  from  the  Leyden  A.  G.  stars  h  and  m  (=+30°  3962  and  3967),  and 
is  almost  identical  with  that  given  by  Hart  wig,  whose  observations  of  the  star's 
variations,  not  yet  published,  seem  to  be  the  only  ones  which  will  be  available 
for  comparison  with  the  present  series.  In  the  Vierteljahrsschrift  39,  261,  Hart- 
wig  derives  the  period  548  days  from  the  interval  between  the  maxima  1899 
August  20  (J.  D.  4887)  and  1904  February  18  (J.  D.  6529),  using  the  divisor  3. 
Reference  to  the  light -curve  (fig.  29)  shows  that  the  divisor  should  be  4,  which 
would  give  410  days  from  the  above  maxima.  This  is  in  close  agreement  with 
the  period  409  days,  derived  from  the  present  series. 

Consideration  of  the  limits  of  visibility  of  the  6-  and  1 2-inch,  renders  it 
probable  that  the  photometric  magnitudes  of  the  stars  fainter  than  p  are  about 
half  a  magnitude  too  small  numerically,  and  therefore  the  minimum  magnitude 
of  the  variable  is  nearer  14.0  on  the  Harvard,  and  14.4  on  the  Potsdam  scales. 

TABLE  80. — 7269  SX  CYGNI.    STANDARD  MAGNITUDE  STARS. 


Star. 

B.  D.  No. 

1900. 

Color 
P.  DM. 

Magnitude. 

Residuals. 

R.  A. 

Dec. 

Catalogue. 

Measured. 

From  Cats. 

3 
Nights 
inter 
se. 

H.C.O. 

P.  DM. 

H. 

P. 

H. 

P. 

E 
F 
G 

o 

+  29  3948 
+  31  4001 
+  31  4020 

Mean    . 

h   m     s 
20  10  15 
20  10  17 
20  12  55 

O                / 

+  29  54.2 
+  31  40.8 
+  31   ii  -9 

VV 
GW 
W 

7-03 
7.38 
6.83 

7-37 
7.58 
7-34 

7.14 
7-'9 
6.90 

7-49 
7-54 
7-25 

+  n 
-19 

+   7 

+  12 

-    4 
—  1  1 

±7 
±3 
±4 

7.08 

7-43 

7.08 

7-43 

±12 

±    9 

±5 

TABLE  Si.— 7269  SX  CYGNI.     COMPARISON  STARS  IN  B.  D.  CATALOGUE. 


B.  D. 

1855- 

B.  D. 

1855- 

Star. 

No. 

Mag. 

R.  A. 

Dec. 

btar. 

No. 

Mag. 

R.  A. 

Dec. 

0 

h  m  s 

o   / 

0 

/<  m  s 

O     / 

m 

+  30  3962 

8.8 

20  9  48 

+  30  49.8 

k 

+  30  3967 

7-7 

20  9  56 

+  30  47.6 

c 

+  30  3963 

9-3 

20  9  48 

+  30  42.2 

I 

+  30  3970 

9.2 

20  10   5 

+  30  2.6 

a 

+  30  3964 

9-1 

20  9  49 

+  30  32.6 

k 

+  3°  3973 

94 

20  IO  48 

+  30  1.9 

b 

+30  3965 

94 

20  9  50 

+30  38.4 

133 


134  RESEARCHES   IN   STELLAR  PHOTOMETRY. 

TABLE  82. — COMPARISON  STARS  FOR  7269  SX  CYGNI  (IN  ORDER  OF  RIGHT  ASCENSION). 


Star. 

Coordinates  from  Variable. 

Light 
Scale, 
Steps. 

Magnitude. 

R.  A. 

Dec. 

Measured. 

From  Curve. 

H. 

P. 

H. 

P. 

ff 

s 

ff 

X 

-118 

-   9-2 

~     79 

'3-5 

12.50 

12.85 

y 

-  63 

-   5-o 

4-      17 

7.0 

13-54 

13.89 

w 

-   55 

-   4-3 

-      32 

10.  0 

'3  i5 

13-50 

s 

-   37 

-    2.9 

4-   225 

24.6 

ii  .00 

"•35 

p 

4-    »7 

+   i-3 

4-    140 

22.4 

11.79 

12.14 

z 

4-   25 

4-    1-9 

4-      18 

o.o 

14.40 

J4-75 

c 

+   30 

4-   2.3 

4-   252 

38.0 

9.61 

9.96 

a 

+   57 

+   4-4 

4-   284 

43-0 

8.83 

9.  18 

n 

4-   59 

4-   4.6 

—        21 

18.4 

11.84 

12.  19 

m 

+   33 

+     2.6 

4-   722 

32-5 

9-44 

9-79 

t 

+   74 

4-   5-7 

4-      10 

ii-5 

13.00 

13-35 

b 

+    78 

+   6.1 

4-     32 

36.2 

9-87 

IO.22 

d 

+  103 

+   8.0 

-     26 

3i-3 

10.50 

10.85 

u 

+  118 

4-  9-1 

-     57 

10.5 

I3-I3 

13-48 

h 

4-  129 

4-10.0 

4-    616 

52.0 

7-44 

7-79 

I 

4-179 

4-13-9 

-2043 

36.6 

9-65 

IO.OO 

f 

+  181 

4-  14.0 

4-    292 

33-3 

10.  10 

10.45 

k 

+  259 

4-20.  I 

-2124 

37-6 

9-5' 

9.86 

g 

+  284 

4-22.  O 

-    251 

34-2 

9.98 

10.33 

TABLE  83. — 7269  SX  CYGNI.     PHOTOMETER  MEASURES  OF  COMPARISON  STARS. 


1904  September  5.                                             6-INCH.                                     Good,  somewhat  dull. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

A    m 
20     5 

20   31 

0 

IO 
13 

F 

GOT 
C 
b 

a 
h 
E 
E 
k 
a 
b 
c 
G 
F 

10.  2     9.9  10.  2 
12.5   13.1   13.0 
29.  7  29.6  29.  i 
29  •  5  30  .  1   30  .  6 

23.5    22.8    23.3 

13.9  14.2  14.2 

9.6     9.8     9.2 

IO.O    IO.2    IO.2 
13.8    14.0    14.5 
24.0    24.2    23.2 
32.1    32.6    33.0 

3r-9  31-7  3'.8 
9.4    9.0    8.4 
11.7  ii  .8  ii.  6 

IO.  10 

12.87 
29.47 
30.07 
23.20 
14.  10 

9-53 
10.  13 
14.  10 
23.80 
32.57 
3'-8o 
8-93 
ii  .  70 

10.90 

0.38 
0.62 
2.76 
2.84 
1.98 
0.80 
0.27 

7-23 
7-47 
9.61 
9.69 
8.83 
7.65 
7.12 

7.58 
7.82 
9.96 
10.04 
9.18 
8.00 
7-47 

30.64 
31-32 
23.50 
14.  10 
9-83 

STELLAR    PHOTOMETRY. 


N 


PLATE  10. 


m 


*'         ' 


.. 


•  * 


.  •         • 


7     ' 


.     n 
u 


.*• 


.  • 


Scale,  i  mm=  13". 6. 


1902  Novenjber-3<3. 


7269  SX  CYGNI. 
R.  A.  2ol>  iim  335.2.     Dec.  +30°  45'  58",  1900. 


CHAPTER  X. — SX   CYGNI.  135 

TABLE  83. — 7269  SX  CYGNI.    PHOTOMETER  MEASURES  OF  COMPARISON  STARS. — Continued. 


1904  October  i.                                           6-INCH.                                                                       Good. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

h    m 

22     4 

22    21 

O 

26 
28 
29 

F 
Gai 
C 
b 
a 
E 
Eai 

E 
a 
b 
c 

Gal 

F 

9.2   10.2     9.2 

13-5  13-5  13-3 
29.7  30.9  30.0 
31.5  32.0  31.6 
26.4  26.2  26.3 
10.6     9.0     9.7 
16.6   15.9  16.0 

IO.2    IO.2    II.  O 

23.2  24.1   23.9 
31.0  31.1  31.9 
30.2  31.0  30.0 
13.0  14.1    13.8 
9-7     9-9     9-3 

9-53 
13-43 
30.20 
31.70 
26.30 

9-77 
16.  17 
10.47 
23-73 
31-33 
30.40 

13-63 
9-63 

9.58 
13-53 
30.30 
31-52 
25.02 

IO.  12 

0.25 
0.72 
2.72 
2.87 

2.13 
0.29 

1.20 

7.14 
7.61 
9.61 
9-76 
9.02 
7.18 
8.09 

7-49 
7.96 
9.96 

IO.  II 

9-37 
7-53 
8.44 

1904  October  2.                                                                                                                              Good. 

22       5 
22    21 

27 
29 

Fa, 
Ga 
h 
c 
b 
a 
Eai 
Eai 
a 
b 
c 
h 

Gal 
Fa. 

'3-5  13-9  14-0 
12.3   13.2   12.5 
10.4  10.  o     9.3 
29.8  29.0  28.8 
30.0  31.0  30.2 
20.  2  20.7   20.  6 

12.5  13.8  13.1 
12.9  13.8  13.4 

22.  I    21  .9    22.3 
30.1    29.8    29.7 
28.9    27.9    28.5 
IO.  I    IO.9    IO.2 
12.4    12.3    12.4 
14.8    14.7    14.2 

13.80 
12.67 
9.90 
29.20 

30.73 
20.50 

13-13 
13.37 

22.  IO 
29.87 

28.43 
10.40 

12-37 
14-57 

14.19 
12.52 

10.  15 

28.82 
30    30 
21.30 
13    25 

0.81 

0.58 
0.29 
2.54 

2-75 
1.74 
0.67 

7-95 

7.72 

7-43 
9.68 
9.89 
8.88 
7.81 

8.30 
8.07 
7.78 
10.03 
10.24 
9  23 
8.16 

1904  October  28.                                           12-INCH.                                 Good,  moon  rising  at  end. 

22  44 

23    o 

32 
34 

m 
hai 
c 
s 

P 
b 
d 
a 
a 
d 
b 

P 
s 
c 
hai 
m 

19.4    19.6    19.9 

9.8  10.1     9.7 

21  .O    21  .7    21  .5 

36.1   35-9  35  9 
42.  i  42.2  41.8 
27.8  26.7  26.0 
30.8  30.8  30.0 
14.0  15.3  14.1 
16.  i   16.0  15.9 
31.9  31.1   30.1 
25.9  26.0  25.8 

43-9  43-7  43-1 
35.2  36.0  35.0 
19.5  20.  i   20.  i 

II.  I    II  .2    IO.9 
2O.  2    21  .1    21.  O 

19    63 
9.87 
21  .40 

35-97 
42.03 
26.83 
30.53 
14-47 

16.00 
31-03 
25-90 
43-57 
35.40 
19.90 
ii  .07 
20.77 

2O.2O 
10.47 
20.65 
35.69 

42.80 
26.37 

30.78 
15    24 

i-73 
0.49 
1.78 

3.27 
4.08 
2.31 

2-74 
1.09 

9  44 

8.20 

9  49 
10.98 
11.79 

IO.O2 

10.45 
8.80 

9  79 

8  55 
9.84 

'I  33 

12.  14 

10-37 
10.80 

9-15 

136  RESEARCHES   IN   STELLAR   PHOTOMETRY. 

TABLE  83. — 7269  SX  CYGNI.    PHOTOMETER  MEASURES  OP  COMPARISON  STARS. — Continued. 


1904  November  i.                                             12-INCH.                                                               Good. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

h    m 

22    2O 

22  35 

o 

28 
30 

a 
d 
b 

P 
s 
c 
hat 

m 
c 
s 

P 
b 
d 
a 

20.  o  19.3  19.8 
36.8  36.1  36.0 
29.2  28.9  29.7 
47-9  47-3  46-9 
38-9  39-t  39-7 
29.2  29.  i   29.2 
15.7  15.8  14.6 
26.9  26.7  25.7 
27.2  26.8  27.3 
41.1  41.3  41.7 
47-7  47-8  48.3 
29-4  29.8  30.3 

35-7  36-9  37-4 
19.4  19.3  19.3 

19.70 
36-30 
29.27 

47-37 
39  •  23 
•  29.17 

15-37 
26.43 
27.  10 
41-37 
47-93 
29-83 
36-67 
19-33 

I9-52 
36.49 
29-55 
47.65 
40.30 
28.  14 

1.65 
3.36 
2.61 

4-59 
3.81 

2-57 
i  .09 

2.32 

8.81 
10.52 
9-77 
"•75 
10.97 

9-73 
8.25 
9.48 

9.  16 
10.87 

IO.  12 
12.  IO 
11.32 
10.08 
8.60 
9-83 

1904  November  3.                                                                                                                         Good. 

23  12 
23  34 

37 
4i 

m 
Aai 

c 

s 

p 
b 

d 
a 
a 
d 
b 

P 
s 
c 
hat 
m 

18.3  19.3  19.2 

IO.I     IO.2     II.  2 
22.8    22.8    21  .9 
36.1    36.0   36.0 

43-o  43.5  43.3 

21  .9    22.7    22.6 
31.8    31.7    31.9 
'5-7    15-1     15-6 

15.4   16.0  15.4 
30.4   30.2    30.4 
24.0   24.2    23.3 

41  .6  41.9  41.2 
35-7  35-2  35.8 
20.  o  20.  o  19.4 

13.8    12.  I     13.0 

19.0  19.7  20.  o 

18.93 
10.50 
22.50 
36.03 
43-27 
22.40 
31.80 

15-47 
15.60 

30-33 
23-83 
41-57 
35-57 
19.80 
12.97 
'9-57 

19-25 
11.49 
21.15 
35-80 
42.42 
23.12 
3'  -07 
'5  49 

1.62 
0.60 
1.84 
3.28 
4.04 
2.04 
2.76 
i  .  it 

9.40 
8.38 
9.62 
ii.  06 
11.82 
9.82 

10-54 
8.89 

9-75 
8-73 
9-97 
ii  .41 
12.17 
10.  17 
10.89 
9.24 

1900  October  17.                                  40-INCH,  WEDGE  II.             Images  very  large  and  unsteady. 

24 

s 

Pd 
n 

y 

•w 

•X 
X 

•w 

y 

n 
d 

P 
s 

22.  0    2O.  I    2O.  O 
32    9   33-0   32.6 

18.8   19.6  19.2 
31.6  32.8  32.0 
48.2  50.0  48.0 
42.0  43.5  43.2 
34-i  35-8  37.2 
32.0  34.9  34.0 
37-4  35-o  36.0 
42.0  40.  i  41.2 
25-9  27.7  23.8 

'3-5    '9-5    20.2 
26.8    24.5    25.9 
18.3    20.0   20.  I 

20.70 
32-83 
19.20 

32-13 
48.73 
42  90 
35-70 
33.63 
36.13 
41  .  10 
25.80 
17-73 
25-73 
'9-47 

20.09 
29.28 
18.47 
28.97 
44.92 
39-52 
34-6? 

1.72 
2.58 
i-5i 
2.56 
4-3« 
3-72 
3-i6 

10.88 
11.74 
10.67 
ii  .  72 

13.47 
12.88 
12.32 

11.23 
12.09 
ii  .02 
12.07 
13.82 

13-23 
12.67 

CHAPTER  X. — SX   CYGNI.  137 

TABLE  83. — 7269  SX  CYGNI.    PHOTOMETER  MEASURES  OF  COMPARISON  STARS. — Continued. 


1902  October  24.                                         40-INCH,   WEDGE  V.                                           Seeing  good. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

MeanScale  Readings. 

c. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

h   in 

21    30 
22   OO 

s 

Pd 
n 

•v 

y 

IV 
X 
X 

w 

y 

n 
d 

P 
s 

15.8  17.0  17.8 
27.0  27.0  26.0 
14.0  12.6  13.3 
28.0  29.2  29.4 
25.7  24.8  24.9 
43-o  43-2  43-6 
40.8  40.3  40.0 
34-5  34-3  34-2 
34-4  34-5  35-o 
39.2  40.7  40.8 
44-8  45-4  44-o 
30.2  27.8  29.4 
15.2   14.8  15.8 
27.5  27.2  27.7 
20.  o  20.  o  20.  o 

16.87 
26.67 
I3-30 

28.87 
25-13 
43-27 
40.27 

34-33 
34  -63 
40-23 

44-73 
29-I3 
15-27 
27-47 
20.00 

18.44 
27-07 
14.29 
29.00 

1.50 

2.38 
1-03 
2-55 

2.21 
4-21 
3-80 

3-  '3 

10.96 
11.84 
10.49 

12.  OI 
II  .67 
13-67 
13.26 
12-59 

11.31 

12.  19 
IO.84 
12.36 
1  2.  02 
14.02 
13.61 
12.94 

44.00 
40.25 
34-48 

1902  November  3.                                              WEDGE  V.                                     Seeing  fair  to  poor. 

i   20 

s 

pd 

n 

V 

y 

Til 
X 
X 

w 

y 

n 
d 

P 

s 

35-2  35-7  35-8 
40.0  40.0  40.0 
25.7  25.8  27.0 
38.0  40.5  41.8 
36.9  36.1  36.8 
56.9  59-8  58-1 
53-o  53-7  54-5 
46.9  47.2  46.7 
46  .  i  48  .  i  47.7 

57-5  57-5  56-3 
58.6  58.7  60.3 
37-7  38.7  39-2 
24.1  25.5  26.9 
39-6  39-4  39-5 
34-o  33-3  33-3 

35-57 
40.00 
26.  17 

40-77 
36.60 

58.27 
53-73 
46.93 
47-30 
57-1° 
59-20 

38.53 
25-50 
39-50 

33-53 

34-55 
39-75 
25-84 
39-65 

3-14 
3-75 
2.27 

3-74 
3-38 
5-43 
5-25 
4-54 

II.  19 
II.80 
10.32 
11.79 

II-43 
13-48 
13-30 
12-59 

II-54 
12.15 
10.67 

12.  14 
11.78 
13.83 
13-65 
12.94 

58-74 
55-42 
47-12 

* 

138 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


is 


13 


MAGNITUDE 
12  II  10 


SO 


7Z69  SX  CYGNI 


10 

n.  . 


FIG.  28. — MAGNITUDE-CURVE  FOR  KX  CYGNI. 


TABLE  84. — 7269  SX  CYGNI.     CONSTANTS  FOR  REDUCTION  AND  COMPARISON  WITH  CATALOGUE 

MAGNITUDES. 


6-INCH. 

Star. 

1904  September  5. 

1904  October  i. 

1904  October  2. 

C. 

Obs.  Mag. 

J  Mag. 

C. 

Obs.  Mag. 

JMag. 

C. 

Obs.  Mag. 

4  Mag. 

H. 

P. 

H. 

P. 

H. 

p. 

H. 

P. 

H. 

P. 

H.        P. 

E  ... 
F... 

G  .. 

0.27 
0.38 
0.03 

7.12 

7-23 
6.72 

7-47 
7.58 
7.07 

+  .09 

-•15 
—  .  ii 

+  .10 
.00 

-  .27 

o.35 
0.25 
-0.03 

7.24 

6.se 

7-59 
7-49 
7.21 

+  .21 
-.24 
+  .03 

+  .22 
-.09 

-0.08 
0.06 
-0.17 

7.06 
7.  20 
6.97 

7.41 
7-55 
7-32 

4-  .03  4-  .04 
-  .18  -  .03 

-1-  .  14   -  .02 

Means. 

Mo.... 

0.23 

7.08 
6.85 

7-43 
7.20 

±.I2 

±  .09 

o.  19 

7.08 
6.89 

7-43 
7.24 

±.16 

±•'5 

—  0.06 

7.08 
7-14 

7-43 
7-49 

±  .12  ±  .03 

12-INCH. 

40-INCH. 

Star. 

Mag. 
6-inch. 

C. 

Star. 

Mag. 
12-inch. 

C. 

Oct.  28. 

Nov.  i.     Nov.  3. 

Oct.  24. 

Nov.  3.    Oct.  17. 

o  

8.91 
9.78 

i  .09 

i.yS 

1.65          i.n 

2  .  6  1              2  .  04 
2-57              1.84 

i 

10.50 
11.79 

11.00 

1.03 

2.38 
1.50 

2.27          1.51 
3-75          2.58 
3.H          1-72 

6  

c  

f  

Hem 

Meat 

Mo    . 

i  C  .  . 

Mea 
Mea 

Mo 

n  C..  .  . 
n  Mag. 

i-73 
9-44 

2.28          1.66 

9-44          9-44 
7.16          7.78 

II  .  IO 

i  .64 

II  .  IO 

9.46 

3  05           i  94 

II  .  IO           II  .  IO 

8.05          9.16 

i  Mag.  . 

9-44 

CHAPTER  X. — SX   CYGNI. 

TABLE  85. — 7269  SX  CYGNI.     MEAN  MAGNITUDES  OF  COMPARISON  STARS. 


139 


6-INCH. 

Star. 

September  5. 

October  i. 

October  2. 

Mean. 

Mag. 

4  Mag. 

Mag. 

4  Mag. 

Mag. 

4  Mag. 

Mag.  H. 

Mag.  P. 

4  Mag. 

E 

7.12 

7-23 
6.88 

—  O.02 
+  0.04 
—  O.O2 

7.24 

7-i4 
6.86 

+  O.  IO 

—  0.05 
—  0.04 

7.06 
7.20 
6  97 

—  0.08 

+  O.OI 

+0.07 

7-H 
7.19 
6.90 

7-49 
7-54 
7-25 

±0.07 
±0.03 
±0.04 

F  .    . 

G  

Mean  

7.08 

7-43 

±0.05 

a  

8.83 
9.69 
9.61 
7-65 

-0.08 
—  0.09 

—  O.O2 
+  O.  II 

9.02 
9.76 
9.61 

+  O.  II 
—  0.02 
—  0.02 

8.88 
9.89 
9.68 
7-43 

—  0.03 

-f-O.  II 

+  0.05. 

—  O.  II 

8.91 
9.78 
9-63 

7-54 

9.26 
10.13 
9.98 
7.89 

±0.07 
±0.07 
±0.03 

±O.  II 

b  

c    .    . 

I,  

Mean  

8.97 

9-32 

±0.07 

12-INCH. 

Star. 

October  28. 

November  i. 

November  3. 

Mean. 

Mag. 

4  Mag. 

Mag. 

4  Mag. 

Mag. 

4  Mag. 

Mag.  H. 

Mag.  P. 

4  Mag. 

a 

8.80 

IO.O2 

9-49 

-0.03 
+  0.15 

—  O.  12 

8.81 
9-77 
9-73 

—  O.O2 
—  O.  10 
+  O.  12 

8.89 
9.82 
9.62 

+  0.06 
+  0.05 

+  O.OI 

8.83 
9.87 
9.61 

9.18 

IO.22 
9.96 

±0.04 
±o.  10 
±0.08 

6    .... 

c    •     .    .    . 

Mean  

9-44 

9-79 

±0.07 

d 

10.45 
7.36 
"79 
10.98 

9  '44 

-0.05 
—  0.08 
o.oo 

—  O.O2 

o.oo 

10.52 
7.41 

"•75 
10.97 

9-48 

+  O.O2 
—  0.03 
—  O.O4 
-0.03 
+  0.04 

10.54 

7-54 
11.82 
it  .06 
9.40 

+  0.04 

+  O.  IO 

+0.03 
+0.06 
—  0.04 

10.50 

7-44 
11.79 
ii  .00 
9-44 

10.85 
7-79 

12.  14 

"•35 
9-79 

±0.04 
±0.07 
±0.02 
±0.04 
±0.03 

h 

p  . 

s  

m  

Mean  

10.03 

10.38 

±0.05 

40-INCH. 

Star. 

October  24. 

November  3. 

October  17. 

Mean. 

Mag. 

4  Mag. 

Mag. 

4  Mag. 

Mag. 

4  Mag. 

Mag.  H. 

Mag.  P. 

d  Mag. 

d  

10.67 
11.74 
10.88 

+  0.18 
-0.05 
-0.13 

10.49 
n  .84 
10.96 

o.oo 
+0.05 
—0.05 

10.32 
ii  .80 
ii  .  19 

-0.17 

+  O.OI 

+0.18 

10.49 
11.79 
ii  .01 

10.84 

12.  14 
11.36 

±O.  12 

±0.04 
±O.  12 

p 

s  

Mean  

II  .  IO 

"•45 

±0.09 

n  .  . 

11.72 

12.88 
12.32 
'3-47 

—  0.12 
—  O.27 

-o.  18 
—  0.07 

12.  OI 

13.26 
12.59 
13.67 

+  o.  17 

+  O.  II 

+  0.09 
+0.13 

11.79 
13-30 
12.59 
13-48 

—0.05 
+0.15 
+  0.09 
—  0.06 

11.84 

13-15 
12.50 

'3-54 

12.  19 
I3.50 
12.85 

I3.89 

±0.08 

±0.18 

±O.  12 
±0.09 

•w  

v.  . 

Mean  

12.76 

13.11 

±O.  12 

140 


RESEARCHES  IN  STELLAR  PHOTOMETRY. 


TABLE  86. — 7269  SX  CYGNI.    VISUAL  OBSERVATIONS  OF  THE  VARIABLE. 


No. 

Date. 

O 

1 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing. 

t. 

"••         ~~- 
A  Mag. 

Month 
and  Day. 

Hour 
C.S.T. 

Julian 
Day 
G.  M.  T. 

Steps. 

Mag. 

i 

2 

3 
4 
5 
6 

7 
8 

9 

IO 

ii 

12 
13 

14 
15 
16 
17 

18 

'9 
20 

21 
22 
23 
24 
25 
26 

27 

28 

29 
30 

3« 

32 
33 
34 
35 
36 
37 
38 

39 
40 

41 
42 
43 
44 
45 

46 

47 

48 
49 
50 

1899 
Oct.    12 

17 
20 

23 
28 
Nov.     3 
8 

J5 
20 

25 
Dec.     4 
19 

27 

1900 
Jan.      2 

22 
24 

31 

Mar.     2 
6 

15 

22 

Apr.     4 
6 
May     i 

2 

ii 

28 
29 
June  13 
23 
July   1  6 
Aug.     6 
8 

»3 
18 
28 
Sept.    4 
15 

21 

Oct.    10 
26 
Nov.  15 
29 
Dec.    ii 
29 

1901 
Oct.    31 

Dec.  21 

1902 
Mar.   28 
July   to 
Oct.      7 

8 
6 

8 

7 
8 
6 
6 
6 
6 

7 
6 
6 

6 
6 

7 
7 
13 
17 

J7 

16 
16 
16 
'4 
15 

12 
12 
IO 
9 
9 
9 
9 
9 
9 
8 

7 
9 
7 
7 
6 
6 
6 
7 

8 
'3 

15 
9 

IO 

2410000+ 
4940.58 

4945  •  50 
4948  •  52 
4951  56 
4956.52 
4962  .  58 
4967  .  50 
4974-50 
4979  50 
4984.50 

4993-54 
5008  .  50 
5016.50 

5022  .  50 
5042  .  50 
5044  52 
5051-52 
5081.79 
5085  .  96 

5094  95 
5101.92 
5114-90 
5116.92 
5141-85 
5142.88 

5151-83 
5168.83 

5169-75 

5194-67 
5217-63 
5238.63 
5240-63 

5245-63 
5250.63 
5260.63 
5267.58 
5278.54 
5284.63 
5303  54 
53I9.54 
5339-50 
5353-50 
5365  50 
5383-50 

5689.58  j 
574°  79 

5837  •  88 
5941.63 
6030.67 

So 

80 
80 
ISO 
150 
150 
"50 
150 
150 
150 
150 
ISO 
ISO 

150 
'SO 
200 
200 
275 
150 

350 

350 

275 
350 
275 
350 
460 

275 
237 
460 
200 
150 
150 
150 
150 
150 
150 
40 
150 
40 
150 
150 
ISO 
'50 
'SO 
'SO 

80 

275 
350 

237 
80 
80 

6 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

6 
6 
6 
6 

12 

6 
40 
40 

12 

40 
12 
40 
40 
12 
40 
40 

6 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

12 

3 

12 
40 

40 
12 
12 

(  vib,  vie,  v^d,  04—51).  .  . 
•<   vik,  V2l,  h&-ioa,  04-51' 

(  VIC,   V2b,   &3/,  J2d,    b2g  . 

06—  7»,  i>ifc,    vie,  V2m.  .  .  . 

CO-IV,  Vl-2b  

37-2,  39-0,  35.3,  38.5 

39-5,  38.5,  38.5  
39  o  38  2  .  . 

'-38.2 

37-6 
37-4 
35-5 
34-8 
34-2 
34-2 
32.2 
32-0 
31.5 

29.8 
28.4 

26.8 

<3>-3 
19.4 

<23 

12.4 
<i8.4 

9.41 

9-52 
9-53 
9.80 
9.90 
9.98 
9.98 
10.26 
10.28 

10.35 
10.31 
10.60 
10.77 

ii  .00 

<io.4 
11.98 

<n.5 

12.89 

13  i  ± 
12.90 
13-31 
13-23 
<I3-0 
13-17 
13.11 
12.98 

12-75 
12.47 
12.31 
11.68 
II-57 
ii.  7± 
11.13 
10.70 
10.  06 
9-85 
9-43 
8.89 

9-37 
9-50 
9.86 
10.39 

10-45 
ii  .20 

8.66 

9.24 

11-43 

<  1  2  .  3 
12.  I± 

moon 

moon 
good 
good 
good 
fair 
fair 
good 
fair 
fair 
good 
fair 
good 

good 
low- 
poor 
low 
good 
fair 

poor 

good 
good 
poor 
poor 
fair 
fair 
good 
good 
fair 
good 
good 
moon 
moon 
good 
good 
good 
moon 
good 

good 
good 
good 
good 
good 
fair 

moon 

good 
good 
good 

o 

5 
8 
ii 
16 

22 

27 

34 
39 
44 
53 
68 
76 

82 
1  02 
104 

141 
146 

155 
162 
'75 
177 
202 
203 

212 
229 
230 
245 
255 
277 
298 
300 
305 
310 
320 
327 
338 

363 

379 
399 
4 
16 

34 
340 

80 

272 

—  O.22 

-o.  18 
-0.24 
o.oo 
+0.03 
o  oo 
—  0.06 

+  O.  IO 

—  0.04 

+  O.O2 

—  o.  20 

—  O.22 
—  O.26 

—  O.22 
—  O.O4 
—  O.  II 

—  O.O4 
-0.32 

—  o.ot 
—  0.07 

+  0.03 
+  0.06 
+0.14 
-0.05 
-0.13 

—  O.  12 

-0.34 
+  0.04 
+  0.23 
—  O.  IO 
-0-37 
-0.28 
+  0.05 
+  O.  II 

4-0.30 
+0.29 
4-0.36 
+  0.69 
+  0.60 

+0.95 

—  0.56 
—  o.  16 

+  0.23 
o  oo 

36.5,  37-2,  39-o,  34-5 
37-o,  37-7  
34.8,  36.2  

biv,  i'3d,  limit  n  

35-3,  34-3  
34.2,  34.  -5  

641',  vid  
641;,  vo-id  
b$v,  vo-id  
651*  vid 

34-2.  34-3  
32.2,  32.3  
32.2,  31.8  
31-2,  31-8  
31.2,  32.3  

dl—2V  .  .  .  . 

0*4—  51?  vio  .  . 

26.8,  30.1  

d^v,  vo,  TJ2-T,p  
v  not  seen  limit  d 

26.3,  29.1,  24.9  

pyv,  vin,  limit  w  
v  not  seen,  limit  4  <  o  .  .  .  . 

19-4,  19.4  

<25I,  <  22  

12-4  

v  not  seen,  n  not  seen 

(i>  is  i  to  i  JM  <n,  v  near^ 
(limit  3 

12.0,  12.5,  12-5  
9.O,  9.0  

9.5,  10.0,  10.0  

12.3 
9.0 
9-8 
<n   5 

10.2 

10.7 

ii.  8 
13-6 
15-9 
16.9 

21.8 
22.6 
21.6 

25-8 
29.0 
33-5 
35-2 
38.1 

1)210,  Vlt,  till,  XIV,  X2VI  .  .  .  . 

wiv,  ti-2v,  v  glimpsed.  .  .  . 
x^v,  Tin,  V3y  
v  suspected,  t  and  y  not  held 
x^v,  viw,  V3y  

n6-8u,  xi-2V,  V2W,  limit  w. 
ni\v,  vx,  vyw,  wioz,  limit  z. 

9.5,  n.o,  10.0  
10.0,  10.5,  11.5  

1  1.4,  I2.O,  12  O  

14.4,  13.5,  13.0  

15.4,  16.5,  16.5,  15.0 

ni—2v,  limit  i  <r  

syv,  Tip,  Tiyi  
S2V,  limit  v  

21.6,  22.4,  21.4  

S3T>,  limit  v  

vi  s,  i'4-5/>,  vSn,  dSv  
div,  V3s  
6311,  vi—  2d  
biv,  v6d  
0511,  vib,  vie  
photometer  

25.6,  26.9,  26.4,23.3 
30.3,  27.6  

33-2,  33-8  
34-2,  37-3  
38.0,  37.2,  39.0  

0511,  1136  
a$v,  TIC,  vib  

64—51*,  do-  iv,  75—  6s  

V1-2O  } 

38.0,  39.2  
38.0,  38.0,  37.2  
35-5.  34-2,  35-3  
31-7,  31-3.  30.6  
31.7,  30.8,  29.9  
25-3,  24.6,  26.4  

38-6 

37-7 
35  o 
31-2 
30.8 

25.2 

43-8 
39  •  5 

23.6 

<i7-4 
18.4 

va  < 

44-5  t 

Iimit6<n,2<«,i  <ic,2<#) 

43-0  ) 

0*5-61',  V3n  
v  not  seen,  limit  i<« 

25.8,  21.4  

i>n  i  

CHAPTER   X. — SX   CYGNI. 


141 


TABLE  86. — 7269  SX  CYGNI      VISUAL  OBSERVATIONS  OF  THE  VARIABLE. — Continued. 


No 

Date. 

1 

8 

1 
i 
& 

< 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing. 

t. 

J  Mag. 

Month 
and  Day 

Hour 
C.S.T 

Julian 
Day 
G.  M.   T. 

Steps. 

Mag. 

5' 
52 
53 
54 
55 

56 

57 

58 
59 
60 

61 

62 

63 
64 

65 

66 

67 
68 
69 
70 
7i 
72 
73 
74 
75 
76 
77 
78 
79 
80 
81 

1902 
Oct.    24 

3' 
Nov.     3 

30 
Dec.   26 

1903 
Oct.    1  1 
'3 

1904 
July   31 
Aug.     3 
27 
Sept.  24 

Oct.     6 

28 
Nov.  30 

1905 
Jan.      3 
Feb.   14 
Mar.  24 
Apr.     4 
30 
May  31 
June  22 
26 
July   26 
Aug     6 

9 
28 
Sept.  23 
Oct.      i 
20 

21 

Nov.  1  8 

8 

9 
10 
8 
'3 

7 
9 

II 

9 

8 

10 
10 

r2 

7 
'7 
'7 
16 

'5 
10 
10 
ii 

9 
10 

9 
9 
7 
10 

7 
9 
6 

2410000+ 
6047  .  58 
6054  .  63 
6057.67 
6084  .  58 
6110.79 

6399.54 
6401  .63 

6693.71 
6696  .  63 
6720.58 

6748.67 

6760.67 
6782. 
6815.75 

6849.54 
6891  .  96 
6929.96 
6940.92 
6966.88 
6997.67 
7019.67 
"023.71 

7053-63 
7064.67 
7067.63 
7086.63 

7"2.54 
7120.67 

7'39  54 
7140.63 
7168.50 

237 
237 
237 

237 
150 

So 

'SO 
67 
'50 

237 
67 
40 

237 
250 
40 
237 
'50 
'50 
'50 
80 
150 
237 
150 
150 
237 
237 
So 

237 
237 

40 
40 
40 

24 
40 

6 

12 

6 

12 

6 

24 
40 

12 

6 

40 
40 
6 
40 
6 
6 
6 

12 

6 
40 
6 
6 
40 
40 

12 
40 
40 

photometer  .               ... 

"•73 
11.85 
11.49 

IO.O± 

8.75± 

12.  6± 

12.  7± 

<'3-» 

13-  2± 
<I2.3 

<'3-2 

'3-6± 

<I2.2 
<I2.2 

12.57 

11.27 
9  50 
8.75 
9-'7 
10.23 

11.25 
11.50 
11-57 
11.80 
12.25 
12.38 
12-73 
13." 

<I2.8 

13.57 
13.37 

good 
fair 
fair 

289 
206 
300 

-0.07 
+  0.26 
+  O.O2 

S$V    pi—  2V,  TJ2W       

20.  6,  20.9,  20.4.  .  .  . 

20.  6 

photometer  

photograph  

wi  ...          . 

43.  ± 

>5-± 
'4-± 

<io.5 

10.  ± 

<'7- 

<IO. 

7± 
<i8 
<i8 

15-0 

24.9 
37-6 

43-o 
40.0 

32-3 
24.9 

23-1 
22.4 
20.9 

'7-4 
16.4 

13-7 
10.5 

<'3-4 
7-5 
8-5 

fair 

.good 
fair 

moon 
good 
moon 

moon 

dull 
good 
good 

fair 
good 
fair 

353 

231 
233 

"9 
'83 

272 
315 

-0.31 

—  o.  19 
-0.03 

+  0.68 
-0.27 

+0.47 
+  0.47 

v  glimpsed,  n$—  $v  

v  glimpsed,  ft4~5"  

TJ  not  seen,  limit  u.  . 

iisv,  vix  
v  not  seen   limit  i—  2<w 

5-5,  '4-5  

(photographs,  i>  not  seen, 
1     limit  2  <w  

i 

i 

•vy,  11  certainly  fainter  thanie 
v  not  seen  limit  n 

v  not  seen   limit  n 

n6v,  vyc,  vGw  
d6v,  v6n,  vs,  v$p  

12.4,  16.5,  16.0  
25.3,  2-4.4,  24.6,  25.4 
38.0,    37.2  

we,  vib  
va  ±  

ay>±  

poor 
fair 
good 
good 
fair 
good 
fair 
fair 
good 
fair 

389 
ii 

33 
37 
67 
78 
81 

100 

126 

'34 

—  o.  19 

+  0.43 
+  I.H 
+  1.29 
+  0.70 
+  0.66 
+  1-03 
+  0.52 

—  O.O2 
+  0.19 

bio—  I2vi    vo—  id 

(2S)     ^2  3 

d6T,  SIT,  "v^p   Tj6n  . 

25-3-    23.6,  26.4,  24.4 
22.6,  24.4,  22.4  

S2V,    T!2p,    Z/4»l  

r/>±,  near  limit.  

d$v,  vin,  piv  

n^V.  bAV  .  . 

26.3,    19.4,    21.4  
I  C  4.      IO  A      . 

n2V,  limit  3  <  w  

vx,   V4W  

XJ^V      "VIV  

13.5,  14.0  

9c       T  j  o 

v  not  seen   limit  5  <C  n 

x6v,  iv  3-41%  wi-2y  

W2V,    TI2y  

7.5,6.5,  8.5  

8.0,   9.0  

good 
good 

154 
182 

+  0.33 
+  O.O7 

142 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


6  «> 


§ 


ft, 


0,10 
?>9 


O 

o 

o 


§ 


0> 

o> 


1 


FIG.  29. — LIGHT-CURVE  OF  SX  CYGNI. 


CHAPTER  X. — SX   CYGNI.  143 

TABLE  87. — 7269  SX  CYGNI.     MEAN  MAGNITUDES  FROM  34.1  DAY  GROUPS. 


Group  No.  .  .  . 
I    D 

i 
-14.  i 

2 

68  2 

3 
102  3 

4 

5 

6 

212    6 

7 

^8    7 

8 
272  8 

9 

10 

ii 

12 

409.  2 

r     t 

J        M 
4940  4     m 

L    No. 

r    < 

12 

9-73 
—  o.  10 

7 

10 

43 
10.30 
-0.03 
4 

34 

75 
10.79 
—  0.23 
3 

104 
11.98 
—  0.04 

i 

153 
12.96 
—  o.  16 
3 

185 
I3-24 
—  O.O4 

3 

224 

12.95 
+  0.05 

3 

250 
12.39 

—  0.  12 

2 

293 
H.52 
—  O.O4 

4 

324 
10.04 

—  O.  12 

4 

-J.1O 

363 
9.37 
4-0.30 
i 

3»9 
9.68 
4-0.32 
2 

j       M 

10.42 

ii  .20 

8  66 

5349  \      m 

+  0.64 

+  0.95 

—  o  56 

I    No. 

2 

i 

r     t 

80 

20=; 

153 

M 

II    43 

8  71; 

5758  \     JM 

+  o  23 

—  O    ^1 

L    No. 

I 

r       t 

212 

M 

12    6^ 

6l6M     JM 

[    No. 

r     < 

1  19 

183 

272 

71  C 

M 

13.  2± 

13  6± 

12    ^7 

II      27 

6577  1     JM 

+  o  68 

4-o  27 

L    No. 

r     « 

i 

i 

I 

I 

J        M 

6986  j      jM 

L    No. 

r     < 

Means]     ^ 
I    No. 

12 
9.88 
—  O.OI 

9 

4i 
10.48 
+  0.16 
5 

76 
10-95 
—  O.  12 

4 

112 

12-59 
+  0.32 

2 

'S3 
12.96 
—  o.  16 
3 

184 

13-33 
4-0.04 

4 

227 
12.83 

—  O.OI 

5 

257 
12.45 
+  0.08 

3 

297 

n-59 

f  O.OI 

7 

324 

1O.OI 

—  0.09 
6 

358 

9.06 
o.oo 

2 

390 

9-53 
4-0.16 

3 

100 


DAYS 
ZOO 


30O 


10 


// 


14- 


500 


7Z69  SX  CYGNI 


Min.  •  IQO<* 
M-m-l73cl 


FIG.  30. — MBAN  LIGHT-CURVE  OF  SX  CYGNI. 


144 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABLE  88. — 7269  SX  CYGNI.    OBSERVED  MAXIMA  AND  MINIMA. 

Elements  of  maximum.     1900  Oct.  2  (J.  D.  241S295)  +  409d  E.     M-ra=1731'. 


MAXIMA. 

MINIMA. 

I 

Date. 

Mag. 

Corr. 

Wt. 

1 
w 

Date. 

Mag. 

Corr. 

Wt. 

Calendar. 

J.  D. 

H. 

P. 

Calendar. 

J.  D. 

H. 

P. 

o 
i 

2 

3 
4 

1900  Oct.     2 
1901    Nov.    i 
1903  Jan.      5 
1904  Feb.  19 
1905  Apr.  ii 

5295 
5690 
6120 
6530 
6947 

9  23 
8.8 
8.8 

8.90 

9.58 
9.1 

9-2 

me 
9-25 

o 

-'4 
+    7 
+   8 
4-i6 

20 

2 
I 
0 

'7 

o 

i 

2 

3 

4 

1900  Apr.   1  6 
1901    May  15 
1902  July     9 
1903  Aug.  23 
1904   Oct.     7 

5126 
5520 
5940 
635f> 
6761 

'3-30 

13  65 
me 
me 
me 
13-95 

+   4 
—  ii 
o 

+    i 
+   3 

33 
i 

7 

2 

7 

13.60 

The  last  observation  used  in  forming  the  mean  light -curve  was  that  of  1905 
February  14,  giving  the  elements  at  the  head  of  Table  88.  The  maximum  of  1905 
April  1 1  indicates  a  slightly  longer  period,  about  410  days.  The  magnitude  at 
maximum  ranges  from  8.5  to  9.2  on  the  Harvard  scale,  the  minimum  about  13.5. 


CHAPTER  XI. 


7458  V  DELPHINI. 
R.  A.   2oh  4301  133.6;  Dec.  +  18°  58'  01"  (1900). 

The  discovery  of  the  variability  of  this  star,  from  the  bright  hydrogen  lines 
in  its  spectrum,  was  made  by  Mrs.  Fleming  at  the  Harvard  College  Observatory 
in  December,  1890.  The  announcement  of  the  discovery  made  in  the  Astrono- 
mische  Nachrichten  127,  5,  gave  the  Right  Ascension  for  1900  as  2oh  41.3™ 
instead  of  43.1"'.  The  other  published  notes  which  have  come  to  the  writer's 
attention  concerning  this  star  are  as  follows: 

Hartwig Astronomische  Nachrichten,    134,    180,   307,    1894. 

H.  M.  Parkhurst Astronomical  Journal,   13,   192,   1894;   IS,  20,   1895;   17,65,   1896; 

21,  9,   190x3;  23,  81,   1903. 
W.  M.  Reed    ...  .^  ...  .Astronomical  Journal  13,  63,  1893. 

Yendell Ibid.,  13,  176,  195,  1893;  17,  79,  1896. 

J.  A.  Parkhurst Ibid.,   16,   178,   1896;   17,   102,  397,   1897;   19,  69,   1899. 

Astrophysical  Journal,   12,  53,   190x3;   14,  176,   1901. 

Visual  observations  began  in  June,  1894,  with  the  6-inch  reflector,  which 
was  supplemented  during  the  summer  of  1898  by  the  1 2-inch  refractor,  and 
after  March,  1900,  by  the  4O-inch  refractor.  The  magnitudes  of  the  comparison 
stars  were  measured  with  the  equalizing  wedge  photometer  attached  to  each  of 
the  telescopes,  connection  being  made  with  the  three  fundamental  stars  from 
the  Harvard  and  Potsdam  catalogues  with  the  6-inch,  and  carried  to  the  fainter 
stars  with  the  12-  and  4o-inch.  Photographs  of  the  field  were  made  with  the 
24-inch  reflector,  insuring  the  correct  identification  of  the  comparison  stars,  and 
furnishing  a  check  on  their  coordinates  from  the  variable,  which  were  measured 
with  the  micrometer  on  the  6-  and  4o-inch. 

POSITION   OF   THE   VARIABLE. 

The  variable  was  connected  with  the  micrometer  on  two  nights,  1 896  October 
24  and  26,  with  the  star  x,  which  is  B.  D.  -(  1 8°  46 19,  and  whose  place  from  the 
Berlin  A.  G.  Catalogue  is: 


R.  A. 

Dec. 

Year. 

Berlin  A   G   Catalogue  8389.    .    . 

h    m       s 

0         /             # 

-f-  1  8    50   21    2 

i8?<; 

Precession  for  25  years  

+     I    O8     12 

+     e    2A    6 

Berlin  A   G   Catalogue  8389 

J-  i«    ec    AC    S 

Difference  variable  minus  x 

Place  of  variable  

20  d.  1   1^6 

-f  1  8  58  oo  8 

IQOO 

This  is  in  close  agreement  with  the  place  found  by  Hartwig  from  heliometer 
measures,  published  in  the  Astronomische  Nachrichten,  134,  307. 

145 


146 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


THE   CHART. 

Plate  1 1  shows  the  field  around  the  variable  on  a  scale  of  i3/'8tothe  millimeter. 
It  is  a  six-fold  enlargement  from  a  negative  taken  1902  September  7,  exposed 
from  9h  17™  to  iou  25™,  Central  Standard  Time,  with  the  24-inch  reflector. 
The  negative  shows  the  star  A,  16.3  magnitude,  distinctly.  The  photographic 
magnitude  of  the  variable  on  this  plate  is  10.4,  which  is  0.6  fainter  than  the  visual 
brightness  as  given  by  the  light-curve,  fig.  32.  This  difference  corresponds 
approximately  to  a  color  of  4  on  Chandler's  scale. 

TABLE  89. — 7458  V  DELPHINI.     STANDARD  MAGNITUDE  STARS. 


1900. 

Magnitude. 

Residuals. 

Star. 

B.  D.  No. 

R   A 

Dec 

Color 
P.  DM. 

Catalogue. 

Measured. 

From  Cats. 

3 
Nights 

H.C.O. 

RDM. 

H. 

P. 

H. 

p 

inter 

se. 

0 

h    m     s 

0            / 

/•' 

+  19  4501 

20  40  17 

+  20  07.9 

G\V 

7.07 

7.  ii 

7.02 

7.28 

-   5 

+  17 

±4 

G 

+  19  4544 

20  47  50 

+  19  45-4 

GW 

7.22 

7-95 

7-55 

7.81 

+  33 

-14 

±2 

K 

+  '9  4555 

20  49  38 

+  19  22.7 

WG 

7.40 

7.40 

/•" 

7-37 

-29 

-    3 

±4 

Mean 

7-23 

7-49 

7-23 

7-49 

±22 

±n 

±3 

i 

THE   COMPARISON   STARS. 

The  data  for  the  comparison  stars  are  collected  in  Tables  89,  90,  and  91, 
which  are  sufficiently  explained  by  the  headings  of  the  columns.  The  difference 
between  the  mean  magnitudes  of  the  three  fundamental  stars  in  the  Harvard 
and  Potsdam  catalogues,  0.26,  is  larger  than  usual,  which  seems  to  be  due  to  the 
Harvard  magnitude  for  the  star  G  being  0.3  or  0.4  too  small.  The  mean  of  three 
measures  in  October,  1883,  is  given  as  6.91  in  Harvard  Annals,  24.  The  mean 
of  three  measures  in  September,  1894,  is  given  as  7.52  in  Volume  44  of  the  same 
Annals.  Whether  this  difference  is  due  to  error  in  the  first  set  of  measures  or  to 
a  change  in  the  star  itself  remains  unexplained. 

TABLE  90. — 7458  V  DELPHINI.    COMPARISON  STARS  IN  B.  D.  CATALOGUE. 


B.  D. 

1855- 

B.  D. 

I855- 

No. 

Mag. 

R.  A. 

Dec. 

No. 

Mag. 

R.  A. 

Dec. 

o 

h  m  s 

0     / 

o 

/;  m  s 

0      / 

£ 

4-18  4602 

8.2 

20  37  56 

+  18  59-3 

n' 

+  18  4617 

9.2 

20  40  26 

4-18  39.7 

( 

+  19  4500 

8.0 

20  38  14 

+  19  M.  J 

m' 

4-18  4618 

9.0 

20  40  29 

4-i8  43.2 

ft 

+  18  4611 

8.8 

2O  40   2 

+  18  43.9 

X 

+  18  4619 

8.9 

20  40  31 

4-iS  45.6 

n 

+  18  4614 

9.1 

2O  40  13 

+  18  55-5 

k 

+  '9  45'3 

94 

20  40  43 

+  19   2.0 

i 

STELLAR   PHOTOMETRY. 
+  30S 


N 
o 


PLATE   11 


-30' 


...» 

•  . 


• 


•  111 


•It- 


•   .•       .v  rt         a»  • 

b*  ® 

Jx  p     .     ' 

f^'    • 
.      •      *V* 


x 

*• 


1-  20' 


— +10' 


10' 


,"  "I  ;mm  =  1 3".  S. 


1902  September  7. 


7458  V  DH 
R.  A.  20h  4310  i;,s.6.     Der.   +18-  58'  i",  1900. 


CHAPTER   XI. — V   DELPHINI. 


147 


TABLE  91. — COMPARISON  STARS  FOR  V  DELPHINI  (IN  ORDER  OF  RIGHT  ASCENSION). 


Star. 

Coordinates  from  Variable. 

Light 
Scale, 
Steps. 

Magnitude. 

R.  A. 

Dec. 

Measured. 

From  Curve. 

H. 

P. 

H. 

p 

It 

s 

„    1 

j 

t 

-984 

-  69-4 

-  30.5          

9.  10 

9-3^ 

n 

-768 

-    54-' 

4-   461 

42.8 

9.87 

10.13 

n' 

—  640 

-   45-i 

-    5'5 

9.82 

10.  08 

m' 

-584 

-   41.2 

-   34° 

9.78 

10.04 

X 

-575 

-   40-5 

-    135 

46.4 

9.29 

9-55 

k 

-391 

-    27.6 

4-    696 

40.  2 

10.28 

10-54 

d 

-336 

-    23-6 

-      28 

33-5 

1  1  .  05 

11.31 

I 

-313 

—     22.0 

-    289 

36.6 

1  1  .  63 

11.89 

c 

—  280 

-      '9-7 

4-      96 

3°-9 

11.31 

"-57 

m 

-194 

-      '3-7 

4-   890 

40.9 

10.  17 

10.43 

i 

-164 

-     11-5 

+    149 

34-5 

1  1  .04 

11.30 

a 

-117 

-        8.3 

4-     48 

27.6 

12.13 

12-39 

K 

-107 

-        7-5 

-    285 

36-4 

10.95 

II  .  21 

to' 

-    76 

5-4 

-     92 

'4-3 

I4.6 

HI 

-   56 

-      3-7 

-    107 

13-73 

'3  99 

(> 

-   45 

-      3-2 

-      7' 

4-5 

'4-7 

15-0 

V 

-    29 

—        2.O 

42 

3-5 

I5-I3 

15-39 

A 

—    20 

I  .4 

c 

l6.2± 

16    *  4- 

n 

-     4 

~        0.3 

-  152 

14- 

14.  I 

14.4 

1  *'  •  o  -C 

!>• 

4-     6 

4-        0.4 

—        12 

2. 

I5-32 

15-5S 

<T' 

+    17 

+        1-4 

-     157 

14.4 

U-7 

— 

+   48 

+     3-3 

+     39 

4- 

'5-2 

15-5 

- 

+  103 

4-      7.2 

-    164 

16. 

13.6 

13-9 

V 

+  104 

+      7-3 

4-     4' 

20. 

13-50 

13-76 



'h 

+  190 

+    '3-5 

+     45 

30.8 

11.63 

11.89 

b 

+  202 

+    '4-3 

-        8 

28.8 

11.94 

I  2.  2O 

e 

+  232 

4-    16.4 

-      64 

33-2 

II  .  30 

II.S6 

s 

-195- 

4-   660 

55-2 

7.81 

8.1 

f 
\ 

-178. 

4-1380 

56.3 

7-7 

8.0 

Table  92  gives  the  determination  of  the  magnitude  of  the  stars  m',  n',  x,  and 
•5,  based  on  the  fundamental  stars  F,  G,  and  K.  No  correction  has  been  made 
for  change  of  atmospheric  absorption  depending  on  difference  of  zenith  distance 
between  the  fundamental  and  measured  stars,  as  it  amounted  to  only  0.002  mag. 
Table  92  also  gives  the  measures  of  a,  c,  d,  j,  g,  and  /,  with  the  1 2-inch  and  the 
fainter  stars  with  the  40- inch. 

In  Table  94  the  separate  results  are  collected  and  the  mean  magnitudes 
found.  The  residuals  for  each  night's  measures  are  given  in  the  column  headed 
4  the  mean  values  being — 

With  the    6-inch ±0.08 

With  the  12-inch ±0.05 

With  the  40-inch ±  o.  1 2 

VISUAL   COMPARISONS   OP  THE   VARIABLE. 

Table  95  gives  in  detail  the  visual  comparisons  of  the  variable  by  Argelander's 
method  with  the  comparison  stars  thus  determined.  There  are  also  included 
for  comparison  the  photometric  measures  of  the  variable  in  observations  Nos. 
112  and  115,  and  estimates  from  the  photograph,  Nos.  114  and  123. 


148  RESEARCHES   IN   STELLAR   PHOTOMETRY. 

TABLE  92. — -7458  V  DELPHINI.    PHOTOMETER  MEASURES  OF  COMPARISON  STARS. 


1903  October  22.                                            6-INCH.                                                              Good. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

c. 

Magnitude 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

h   m 

21       6 
31    32 

0 

25 
25 
25 
26 

26 
26 

F 
G 
K 

X 

m' 
n' 
K 

S 
n' 
m,' 

X 

K 
G 

F 

12.9  12.8  12.8 
17.6  16.8  16.9 
J3-5  13-6  13.7 
32-5  32-7  32-8 
36.6  36.8  37.0 
36.5  36.1  36.0 
32.7  32.0  32.1 
50.2  50.7  50.2 
31.9  32.1  31.0 
35-2  35-4  35-0 
36.1  36.2  35.4 
33-2  33-o  33-2 
>3-4  '3-9  13  6 
17.1   17.4  17.0 
12.5  12.3  12.4 

12.83 
17.  10 
13.60 
32.67 
36.80 
36.20 
32-27 
50.37 
31-67 
35-20 
35-90 
33-13 
13-63 
17.17 
12.40 

12.62 
17.14 
13.62 
32.90 
36.35 
35-70 
3i  97 

0.59 
1-25 
0.74 
3.04 
3.50 
3.42 
2.92 

4-73 

6.96 
7.62 
7.11 
9.41 
9.87 
9-79 
9  29 

II  .  IO 

7.22 

7.88 

7-37 
9.67 
10.13 
10.05 
9-55 
ii  .36 

IQ03  October  23.                                                                                                                            Good. 

21     4 

21    24 

26 

27 

d 
n' 
m' 

X 

K 
G 
F 
F 
G 
K 
•x 
m' 
n' 
S 

28.6  28.8  28.9 
32.1  32.7  32.6 
33.1  32-9  33  3 
3i-3  31-4  3I.5 
12.5   12.3  12.  i 

'5-9  15-3  IS-? 
12.  i   ii  .8  ii.  8 
10.7  i  I.  i   10.4 
15.1   15.2  15.5 

II.5     12.  I     12.3 

28.9  29.9  29.0 

31-7  32.7  32.5 
32.0  32.2  32.3 
31.0  30.2  30.8 

28.77 

32-47 
33-10 
3I-40 
12.30 
15  63 
11.90 
10-73 
15-27 
H-97 
29.27 

32-30 
32-17 
30.67 

29.72 
32-32 
32.70 

30.34 

12.  14 

15-45 
11.82 

2.66 
2.97 
3  oi 

2.  72 
0.52 

o  99 
o.49 

9.  22 
9-53 

9-57 
9.28 
7.08 
7-55 
7-05 

9.48 
9-79 
9.83 
9-54 
7-34 
7.81 

7-31 

1903  October  24.                                                                                                       Good,  small  moon. 

20  47 

21       8 

23 
24 

25 

24 

F 

IF;; 

G 

K 

X 

m' 
n' 
3 
d 
n' 
m' 

X 

K 
G 
F 
F0. 

10.  7   10.  7   1  1  .0 
15.7    16.0   16.6 

13-9   14.4   13-7 
ii  .6   12.  i    11.7 

30.5  30.7  30.1 
31.6  31.7  32.1 
32.2  32.0  32.0 
30.2  29.2  29.7 
30.6  30.1  30.1 
32.1  31.7  31.3 
32.2  32.0  32.4 
30.5  31.0  31.2 
11.3  11.5  11.3 
14.4  14.3  13.4 

10.6  10.7   10.7 
17.2   17.4   17.1 

10.80 
16.  10 
14.00 
ii  .80 

30  43 
31.80 
32-07 
29.70 
30.27 
31-70 
32.20 
30.90 

11-37 
14  03 
10.67 
17-23 

10.74 
16.67 
14.02 

11-59 
30.67 
32.00 

31.89 
29.99 

0.28 
1.17 
0.80 
0.46 
2.76 
2.94 
2.91 
2.68 

6  97 
7-86 

7-49 
7-15 
9  45 
9  63 
9.60 
9-37 

7-23 

8.12 

7-75 
7.41 

9-71 
9.89 
9.86 
9-63 

CHAPTER   XI. — V   DELPHINI. 


149 


TABLE  92. — 7458  V  DELPHIM.     PHOTOMETER  MEASURES  OF  COMPARISON  STARS. — Continued. 


1903  October  25.                                            12-INCH.                                                              Fair  to  good. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3 

Mean  of  6. 

H. 

P. 

A    m 
23   >5 

23  45 

o 

40 

45 

X 

m' 
n' 
d 
I 

S 

a 

f 
c 
d 

f 
a 

S 
<5 
n' 
m' 
.r 

21  .0  21.8  21.3 
24.9  25.8  25.2 
27.4  28.2  27.9 

19.8    20.  I     2O.3 

43-3  44-o  44.5 
38.0  37.7  38.1 
49-9  50.2  49.0 
38.8  37.9  38.0 
40.0  39.3  39.2 
38.7  37-7  38.2 
39  4  39-o  39  o 
49.1  50.0  49.9 
38.2  38.0  37.8 

2O.  I     19.7    20.  O 
26.9    27.0    27.0 
28.2    27.7    27.3 
21.9    23.0    22.3 

21.37 
25-30 
27-83 
20.87 

43  •  93 
37-93 
49.70 

38-23 
39  50 
38.20 

39.13 
49.67 
38.00 

19  93 
26.97 

27-73 
22.40 

21.89 
26.52 
27.40 
20.00 

1.91 

2-33 
2.40 
1.71 
4.  20 
3  54 
4-77 
3.62 

3-72 
3-57 

9-32 

9-74 
9.81 
9.12 
ii  .61 
10-95 
12.  18 
11.03 

11.13 
10.98 

9.58 

10.00 

10.07 

9-38 

11.87 

II.  21 
12.44 
11.29 

u-39 
11.24 

37-97 
49.69 
38.68 

1903  October  26.                                                                                                                Good,  moon. 

21       3 

21  31 

24 
26 

(5 
n' 
m' 

X 

d 
c 

/ 
a 

g 

J 

g 
a 

/ 
c 
d 

X 

m' 
n' 
S 

18.2   18.7   19.0 

24.6  25.3  24.9 
25.0  26.0  25.4 

2O.  I     19.9    20.  I 
38-3    38-3    38.8 
4O.8    40.7    40.9 

37-2  37-o  37.2 
46.  7  48.0  47.  i 
36.7  37-6  37.0 
41  .  i  42.0  41  .0 
41  .6  41.9  42.  i 

37-4  35-4  36.4 
46.7  47.8  47.3 
36.9  36.0  36.6 
40.2  40.0  39.  i 
36.8  36.3  36.4 
19.8  19.3  19.9 
24.7  24.2  24.7 
23.7  23.6  23.7 
18.2   18.3   18.5 

18.63 
24-93 
25-47 
20.03 

38.47 
40.80 

37-'3 
47-27 
37-io 
4'-37 
41.87 
36.40 
47-27 
36-50 
39-77 
36-50 
19.67 

24-53 
23.67 

18.33 

18.48 
24-30 
25.00 
19-85 
37-49 
40-29 
36.82 
47-2? 
36.75 
41  .62 

i-50 
2-15 

2.20 

1.68 

3-48 
3.80 
3-40 

4-55 
3-40 
3  96 

9.12 

9-77 
9.82 
9-30 

II  .  IO 

ii  .42 
1  1.  02 

12.  I? 
II  .02 
11.58 

9-38 
10.03 
10.08 
9-56 
11.36 
11.68 
11.28 

12-43 
11.28 
11.84 

1903  November  10.                                                                                                                       Good. 

21    38 
22      2 

26 
29 

S 
n' 
m' 

X 

d 
c 

f 
a 

g 

g 
a 

/ 
c 
d 

X 

m' 
n' 
S 

'1.2     12.  I     12.2 

18.0  18.7   18.8 

16.7    17.7    17.2 

14-3    I3-I    13-8 
30.8    30.9    31.8 

33-8  34-o  33.3 
30.8  30.0  30.1 
4:  .  i  40.0  40.4 
28.5  29.0  28.2 
36.0  37.0  36.2 
28.9  29.2  28.9 
38.1  38.0  38.0 
31.0  30.9  31.2 
33-2  33-9  34  2 
30.0  30.8  30.7 
14  .3   14.3  14.3 
18.7   19.0  18.6 
19.0  18.6  19.1 
12.2   13.8  13.1 

11.83 
18.50 
17.20 
'3-73 
3'-i7 
33-70 
30-30 
40.50 
28.57 
36.40 
29.00 
38.03 
31-03 
33-77 
30-50 
14.27 
18.77 
18.90 
13-03 

12.43 
18.70 

17-99 
14.00 
30.84 

33-74 
30.67 

39-27 
28.79 

0.71 
1-55 
i-45 
0.91 

2-74 
3-05 
2.72 
3-70 
2-53 
3-35 

9  05 
9-89 
9-79 
9-25 
11.08 

"•39 
n  .06 
12.04 
10.87 
ii  .69 

9-3» 
10.  15 
10.05 
9-51 
u-34 
11.65 
11.32 
12.30 
11.13 
"•95 

150 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABLE  92. — -7458  V  DELPHINI.     PHOTOMETER  MEASURES  OK  COMPARISON  STARS. — Continued. 


1900  July  26.                                                 40-INCH,  WEDGE  II.                                                 Twilight- 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

h    in 

O 

d 
c 

i 

a 
V 
"/ 

S 
a 

t 
c 
d 

18.5  18.3  18.3  18.8 

23.  2    22  .  2    23.  2    22.  2 
18.2   19.8   16.8   16.7 
27.8    25.  I    25.5    26.9 
36.0   37.5    35.5    36.2 

18.48 
22.70 
IS.  13 
26  -  33 
36  -  30 
20.00 
15-35 
23-53 
14-65 
19-73 
14.48 

16.48 
21.72 
16.39 
24  •  93 

0.92 

'•77 
0.91 
2.23 
3-52 
15 
0.72 

10.84 
ii  .69 
10.83 

12.  15 

13-44 
II.4 
10.6 

II  .  10 

ii-95 
I  I  .09 
12.41 
I3-70 

ii-7 
10.9 

14  5  16  2   .    . 

22.5    23.9    22.8    24.9 

13.2  14.8  14.9  15.7 
19.8  20.9  19.9  18.3 
14.2  15.0  13.9  14.8 

1900  August  30. 

19  5° 
20  20 

i 

a 

y 
» 
ft 
c 
f 
i» 
/• 
ft 

•R 

y 

a 
i 

16.5  16.5  17.2 
27.0  27.2  24.9 
31.8  32.1  33.3 
52.0  50.0  50.9 
49-9  54-7  53-6 
5'-i   52-3  51-9 
46  .  8   

16.73 
26.37 
32  .  4° 
50.97 

52.73 
51.77 
46.8 

37-13 
51.80 

51-43 
50.80 

34-17 
21.97 

'3-33 

15  03 
24-17 
33-29 
50.89 
52.08 
51-79 

0.71 
2-13 

3-22 
5-03 
5-13 

5-u 
4-7± 
3-62 

10.87 
12.29 
13-38 
'5   19 
15-29 
15-27 
«4-9± 
13-78 

11.13 
12.55 
13-64 
15-45 
15-55 
15-53 
15.  i± 
14.04 

36.1  38-5  36.8 
53.0  50.2  52.2 

50.3  50.9  53  i 
50.9  49.8  51.7 
33-3  35-2  34  o 
23.2   20.9  21  .8 
12.4   15.0   12.6 

1900  September  6.                                                                                                            Moon  too  bright. 

21  47 

22       5 

d 
c 

f 
a 

y 

w 

1.5.2   16.2   15.6 
18.9  19.9  20  .  I 
16.0  12.  o  14.4 

22.0    24.2    25.7 

37-9  34-3  35-o 
38-9  39-6  37-7 

15.67 
19-63 
1-4-  13 
23-97 
35-73 
3»  •  73 

0.80 

i-43 
0.58 

2.  IO 
3-46 

3-79 

10.95 
11.58 
10.73 
12.25 
13.61 
13  94 

II.  21 
11.84 

10.99 
12.51 

13-87 
I4.2O 

1900  September  13.                                                                                                                        Good. 

22    22 

22  57 

d 

c 

} 

a 

y 

IJL 
f> 

V 

IU' 

to 
a 
n' 

y 

a 
/ 

/ 
c 
d 

16.5   15.1    15.9 
19.2   18.2  17.8 
12.  o   II.  8   12.3 

25.0  25.9  23.4 

35-2  35-7  32-5 
52.1   52.0  51.9 

47-5  46.9  47-8 
41.  o   

15.83 
18.40 
12.03 
24-77 
34-47 
52.00 
47.40 

15-7° 
18.09 
12.88 
24-39 

34-32 

0.80 

I  .21 

0.40 
2.16 
3.32 

5-12 

4.75 
4.  3d: 

ii  .04 

"•45 
10.64 
12.40 
13-56 
15-36 
14-99 
M-5± 
14-  3± 
13-  1± 
14.  i  ± 
M-4± 
i3-9± 

I  I  .  3O 
11.71 
I0.9O 

12.66 
13.82 
15.62 
15-25 
14-  »± 
M-6± 
13  4± 
i4-4± 
«4-7± 

14-  2± 

34-17 
24.00 

1  1  -  33 
13-73 
17-77 
15-57 

4-i± 

2.9± 

3-9± 

4-2± 

3-7± 

10  * 

•?Q  8    . 

37  7 

34-8  33-9  33-8 
23.8  24.2  24.0 
ii.  o  11.9  ii  .  i 
13.2  14.5  13.5 
17.  i   19.0  17.2 
14  9  16.6  15.2 

CHAPTER   XI. — V   DELPHINI. 


151 


TABLE  93. — 7458  DELPHINI.    CONSTANTS  FOR  REDUCTION  AND  COMPARISON  WITH  CATALOGUE 

MAGNITUDES. 


6-INCH. 

1903  October  22.                           igov 

(  October  23.                          1903  October  24. 

Star.                   Obs.  Mag.        J  Mag.                    Obs 

.  Mag.        J  Mag.                  Obs.  Mag.         J  Mag. 

H.        P.        H.       P.                   H. 

P.        H.        P.                  H.       P.        H.        P. 

F         .  .    o  S9      6  96    722  —    1  1  +    1  1    o  49    7  o 

5      7.31    —  .02  -f  .20     0.36     6.97      7.23—  .10  +  .  12 

5    7-8i  +  -33  -  -H    0.80    7.49    7.  75  +  .  27-.  20 
8    7.34—  .32—  .06    0.46    7.15    7.41—  .25—  .01 

G  .             i   25      7  62    7  88  +    41  —   06    0.99    7  5 

K  .     ...     o  74      7   ii    7  .  37  —  .  29  —  .03    0.52    7.0 

Means..    0.86      7.2-?    7.  49  ±.27  ±.07    0.67    7.2 
M0  6.37    6.63  6.5 

3    7-49±-22±.i3    0.54    7.23    7.49  ±  .21  ±  .11 
6    6.82  6  .  69    6  .  95  

12-INCH. 

40-INCH. 

C. 

o,               Mag. 

C. 
^                   Mae. 

n-  Oct.  25.    Oct.  26.    Nov.  10. 

"'July  26.  Aug.3o.Sept.6.Sept.i3 

m'  9-69        2  .  33          2  .  20          '-45 

a   12.13        2.23        213      210     216 

nf                     o  64.        2  4.0          21^           i    ^s 

x  9-38        i  91           i  68          o  91 

d           ..ii  05        o  92             .        o  80     o  80 

Mean  C           ....        2  09          i  88          i   16 

Mean  Mag.     9  .  50        9  .  50          9  .  50          9  .  50 

M,,  .                                             7417    62              8    "?4. 

Mean  Mag  .     n  .  84      1  1  .  38      11.58    1  1  .  38    1  1  .  38 
M0  .  .               9  92      10  16    10  15    10  24 

MAGN 
17                     16                       IS                      /•»                       13 

TUDE 
t£                     II                     IO                     9                      6                    7 

EEEEEEiEEEiEEEJEEEEijEEEiEEiEiiiEEEEEEEEjiiifE!!! 

SO  •• 

q:  ;:  :t  :i  — 

7459  v  DELPHI  NI  :; 

4O  

30  i 
11    1  lllllll  lllll 

\rm\              I  llP 

IO   •- 
O  -*--!  •'  J  "f"I" 

i  —  ^4-  -  -  -  "  i 
j.::i::::::::i::  :: 

.</»  1  [  1  1  1  1  1  1  1  1  1  i  I  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  .  1  1  1  1  1  1  1  1  1  1  1  1  1 

-  —  -H-  -pr 

i                                                                            I 

FIG.  31. — MAGNITUDE-CURVE  FOR  V  DELPHINI. 


152 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABLE  94. — 7458  V  DELPHINI.     MEAN  MAGNITUDES  OF  COMPARISON  STARS.  » 


6-INCH. 

Star. 

October  22. 

October  23. 

October  24. 

Mag. 

A  Mag. 

Mean. 

Mag. 

J  Mag. 

Mag. 

d  Mag. 

Mag. 

d  Mag. 

Mag.  H. 

Mag.  P. 

A  Mag. 

F      ... 

6.96 
7.62 
7.11 

—  0.06 
+  0.07 
o.oo 

7-05 
7-55 
7.08 

+  0.03 
o.oo 
-0.03 

7.04 
7-49 
7-i5 

4-O.02 

+  0.06 
+  0.04 

7.02 
7-55 
7   11 

7.28 
7-81 

7-37 

±0.04 
±0.04 
±0.02 

c,  

K    

Mean  . 

m'  .    ... 

7-23 

7-49 

±0.03 

9-8? 
9-79 
9.41 
9.29 

4-0.18 
+  0.15 
+0.03 
o.oo 

9-57 
9-53 
9.28 
9.22 

—  O.  12 
—  O.H 
—  O.  IO 
—  0.07 

9-63 
9.60 

9-45 
9-37 

—  0.06 
—  0.04 
+  0.07 
+  0.08 

9.69 
9.64 
9-38 
9.29 

9-95 
9.90 
9.64 
9-55 

±O.  12 
±0.  10 
±0.07 
±0.05 

n'      

%  

3  

Mean. 

9-50 

9.76 

±0.07 

12-INCH. 

Star. 

October  25. 

October  26. 

November  10. 

Mag. 

d  Mag. 

Mean. 

Mag. 

J  Mag. 

Mag. 

9.82 
9-77 
9-3° 
9.12 

d  Mag. 

Mag. 

4  Mag. 

Mag.  H. 

Mag.  P. 

d  Mag. 

m'  .    ... 

9-74 
9.81 
9-32 
9.12 

—  0.04 

—  O.OI 

+0.03 

+  O.O2 

+  0.04 
-0.05 

+  O.OI 
+  O.O2 

9-79 
9.89 

9-25 
9-°5 

+  O.OI 

+  0.07 
—  0.04 
-0.05 

9.78 
9.82 
9.29 
9.  10 

10.04 
10.08 
9-55 

<)  •  S<> 

±0.03 
±0.04 
±0.03 
±0.03 

n'    

%  

ft 

Mean  . 
a   

9-50 

9.76 

±0.03 

12.  18 

11.13 

10.98 
11.03 

JO  95 
ii  .61 

+  0.05 

-0.18 
—  0.07 

—  O.OI 

o.oo 

—  O.O2 

12.  17 
ii  .42 
1  1  .  i  b 
ii  .02 
ii  .02 
11.58 

+  0.04 

+  O.  II 

+  0.05 

—  O.02 

+  0.07 
—  0.05 

12.04 

"•39 
11.08 
ii  .06 
10.87 
ii  .69 

—  0.09 
+  0.08 
+  0.03 

-f0.02 
—  0.08 
+  O.O6 

12.13 
11.31 
11.05 
ii  .04 

10.95 
11.63 

12.39 
ii-57 
H-34 
n-32 
11-13 
H-95 

±0.06 

±O.  12 

±0.05 
±0.02 
±0.05 
±0.04 

c  

d  

f 

Mean  . 

"•35 

ii.  61 

±0.06 

40-INCH. 

Star. 

July  26. 

August  30. 

September  6. 

September  13. 

Mean. 

Mag. 

d  Mag. 

Mag. 

d  Mag. 

Mag. 

4  Mag. 

Mag. 

J  Mag. 

Mag.  H. 

Mag.  P. 

d  Mag. 

*  n 

12.15 
ii  .69 
10.84 
10.83 

—  0.  12 
+  O.  12 
—  O.  IO 
4-0.06 

12.29 
10.87 

+  0.02 
4-O.  IO 

12.25 

11.58 
10.95 
J0.73 

—  O.O2 
+  O.OI 

4-0.01 
—  0.04 

12.40 

Ji-45 
ii  .04 
10.64 

4-0.13 
4-o.  12 
-f  o.  10 
-0.13 

12.37 
n-57 
10.94 
10.77 

12.53 
11.83 
1  1.  20 
ii  03 

±0.07 
±0.08 
±0.07 
±0.08 

c    .    ... 

d   

f 

Mean  . 

y    

11.38 

ii  .64 

±0.08 

13-44 

—  O.O6 

>3.38 
i4-9± 
15-29 
15   19 
15-27 
I3-78 

—  O.  12 

-0.03 

13-61 

+  O.  II 

I3-56 

14-  5  ± 
I5-36 

+  0.06 
+  0.04 

13-50 

H-7± 
15-32 

15-  2± 

15-13 
13-73 

H-3± 
14.  i± 

i4-4± 

13-76 
15.  o± 
15-58 
i5-5± 
15-39 
'3-99 
14-  6± 
i4-4± 
i4-7± 

±0.09 
±0.04 

±o.  14 

f 

ij. 

It         .... 

/>   

4-o.  14 
+0.05 

13-94 

+  O.2I 

14.99 
13-  1± 
14-  3± 
Id.    I  4- 

—  o.  14 

ru' 

„> 

i4-4± 

CHAPTER   XI. — V   DELPHINI. 

TABLE  95. — 7458    V  DELPHINI.    VISUAL  OBSERVATIONS  OP  THE  VARIABLE. 


153 


No. 

Date. 

Ocular. 

Aperture. 

Comparisons. 

V 

Reduction,  Steps. 

Means. 

Seeing. 

/. 

J  Mag. 

Month 
and  Day. 

Hour 
C.  S.T 

Julian 
Day 
G.  M.  T. 

Steps. 

Mag. 

i 

2 

3 

4 
5 
6 

7 
8 
9 

10 

ii 

12 

'3 

14 
15 

16 

'7 
18 

19 

20 
21 
22 
23 

24 

25 
26 

27 

28 

29 
30 
31 

32 

33 
34 

35 
36 

37 
38 
39 

40 

4i 
42 
43 
44 
45 

1894 
June  28 

30 
July     6 

23 
Aug.     6 
Nov.  20 
Dec.     2 

13 

19 
25 

'895 
Jan.    15 
Feb.   21 

May   26 

June  13 
26 
July     9 
'9 
24 
30 
Aug.  12 

25 
26 

Sept.    6 
10 

1896 
Aug.  10 
26 
Sept.  23 
Oct.      5 

24 
26 
Nov.     i 

12 

14 

22 
26 

Dec.     2 
9 

12 
2O 

1897 

Jan.      6 
28 
May   28 
July     8 
Aug.  27 
Oct.    14 

10 

10 
10 
10 
10 

6 
6 

6 

6 
6 

6 
10 

IO 
10 

9 
9 
9 
9 
9 
8 

9 

8 
8 

9 
8 

8 
6 

8 
8 

7 
6 
6 

8 
8 

6 

7 
7 

6 
6 

IO 
9 
9 

7 

2410000  + 
3008.67 

3010.67 
3016.67 

3033-67 
3047.67 

3i53  50 
31*5.30 

3176  50 

3182.50 
3188.50 

3209.50 
3246. 

3340.67 

3358.67 
3371-67 
3384.63 
3394.63 
3399.63 
3405  •  63 
3418.60 
343L58 
3432-63 
3443.58 
3447.58 

3782.63 
3798.58 
3826. 
3838.58 
3857-50 
3859-58 
3865  .  58 

3876  .  54  -J 
3878.50 
3886.  50  | 

3890.58 
3896.58 

3903-5o{ 
3906.54 
39I4-  54  { 

393".50 
3953-50 
4073.67 
4114.63 
4164.63 
4212.54 

150 

150 
150 
150 
150 
150 
'50 

150 

150 
150 

150 
150 

150 

150 
150 
150 
150 
150 
150 
150 
150 
'50 
150 
40 

150 
150 
80 
150 
80 
80 
150 
150 
40 
150 
15° 
40 
40 
40 
150 
40 
80 
150 
40 

'50 
150 

6 

6 
6 
6 
6 
6 
6 

6 

6 
6 

6 
6 

6 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

6 
6 
6 

fgi/,  }2g,  ec,  eid,  d^b  

I 

<I2 

<I2 
<I2 

<I2 

(C2a,  ti2b,  eT,h,  limit  Ka 
e^h,  Ii2b,  g2e,  g3/   cif   ab   . 

J  ' 

J2C,  cid,  d$e,  €4—50,  ab  .  .  .  . 

€1—2(1     £2f     fid 

nothing  visible  in  place  of  v 
fid,  d2c,  c^a,  bia   limit  a. 

37-9 
36.2 
32.7 
31-5 
31.0 

30.9 
28.0 
27.1 
25.6 
25.6 

<I2 
<I2 

<I2 

<I2 
<I2 

<I2 
<I2 

n>.  di 

10.92 
II  .40 

"•57 
11.63 
11.66 
12.03 

12.  15 

12.35 
12.35 

<n-4 

<I2 

<I2 
<I2 
<I2 

12.36 
IO.O9 

9-95 
9-83 

9.60 

9-35 

9.48 

9-45 
9-40 

9-77 
9-95 
10.08 

10.40 
II  .  II 

<n.3 

<I2.3 
<I2.6 
<I2.5 

C2a,  ao-ib  

(62a   J2d   d$c   czb 

\. 

i.bi—2a,  limit  a  
}id,  d^—^c,  c^a,  b2a  

) 

C2—  30   bia 

C2—  3<z,  limit  a  

nT,d,  040  

fa  is  not  the  var.  v  is  in  line 
1  cae,  r3/,  k$v  

Ill,  VI-2J,  T)2-$d  
J2V,     V2C  

'5",  fy>,  T40  
fyv,  uyi  
d2v,  vie,  f$v,  v^u  

) 

good 

good 
good 
fair 
fair 
fair 
moon 
good 
fair 
good 
fair 
good 

fair 
good 
fair 
good 
fine 
fine 
good 

good 
good 
good 

good 
good 

fair 
fair 
poor 

fair 
low 
low 
moon 
good 
good 

6 

24 
37 
50 
60 
65 
7i 
84 
97 
98 

504 
523 
525 

2 

'•3 
13 

23 

27 
33 
40 

43 
5i 

68 
90 

+  0.82 

+  1.26 
+  1.50 
+  1-37 
+  1.23 
+  1  .  14 
+  1.23 
+  1.17 
+  1.08 
+  1.04 

+  I.2O 
—  O.  IO 
-0.15 

—  O.07 

-0.08 
-0.30 

-0.17 

—  O.26 
—  0.41 

—  O.2O 
—  O.  IO 
-0.13 

—  O.2I 
+  O.OI 

39.6,  36.2  $ 
36.6,  36.0,  36.0  
32.5,  32.9  
31-6,  31-5,  3'.6  
31.5,  30.6  
31.5,  31.9,  29.5,  30.6 
26.9,  29.1  

C$V,   VI—  2O  

ej—  811,  vo,  

276    26  7    . 

a2v,  limit  "V  

a2v,  limit  v  

v  not  seen   limit  c     ... 

"v  not  seen   limit  a     ... 

V  not  seen,  limit  2<a  

v  not  seen   limit  a 

a2v,  limit  v  

25.6 

41.8 
42.8 
43-5 

45-1 
46.9 
46.0 

46.3 
46.6 

44.2 
42.8 
42.0 

39-7 
34-5 

vk,  vim,  xyi  
xyv,  112k  

XI-2V,  V2k  

xiv,  v6m,  vs~6k  
xi—  2V,  115—  6k,  713—  4n  

VO-  IX,  

40.2,  41.9,  43.4.  .    .  . 
43-4,   42.2  
44.9,  42.2  

44-9,  45-7,  46.3-  •  •  I 
45-4,  46.9.  45-7-  •  •/ 

VIX  

47.4  ) 

xiv,  V2-$n  
xo-iv,  714*1  
xiv,  v$n  

X2V  

45-4,  45-0  I 
45-9,  46.8  
45-4,  47-8  

44.4  •  .                           .  1 

xyv,  V2n  
XJ.V,  vtn,  V2k  

«  211,  V2k  

x^v,  vn  

k3V,vsl,v6f  
•vf      

43-4,  44-8  / 
42.4.  43-8,  42-2  
42.4,  42.8  1 
40.8,  42.2  / 

37.2,  41.6,  40.5  

v  not  seen,  limit  d  

v  not  seen,  limit  2<a  

v  not  seen  limit  3—4  <  a  .  .  . 

f  not  seen,  limit  3<Cfl  

154  RESEARCHES   IN   STELLAR   PHOTOMETRY. 

TABLE  95. — 7458  V  DELPHINI.    VISUAL  OBSERVATIONS  OF  THE  VARIABUJ. — Continued. 


No. 

Date. 

Ocular. 

a 

1 
I 

< 

Comparisons. 

Reduction,  Steps. 

Meaus. 

Seeing 

I. 

1 

4  Mag 

Month 
and  Day. 

Hour 
C.S.T. 

Julian 
Day 
G.  M.  T. 

Steps. 

Mag. 

46 

47 

48 

49 
5° 
51 
52 
53 
54 
55 
56 

57 

58 
59 
60 
61 
62 
63 
64 
65 
66 

67 
68 

69 
70 

7i 
72 
73 
74 
75 
76 
77 
78 
79 
80 

81 
82 
83 

84 

85 
86 

87 
88 
89 
90 
9i 
92 

93 
95 
96 

97 
98 
99 

1898 
Feb.   15 
Mar.     2 
15 
23 
April    i 

15 
June  19 

21 

July     7 
18 
Aug.     9 

i? 

1899 
Jan.     9 
Mar.  22 
Apr.    1  6 
May    10 
29 
June     7 
10 
26 
July     8 
Aug.  10 

22 
30 

Sept.    4 
20 

Oct.        2 

6 
18 

24 
Nov.     3 
8 
15 

22 
26 

Dec.     7 

19 

28 

1900 
Jan.      4 

24 
Mar.     2 
May      i 

3 
ii 
June     8 
19 

28 

July   20 
25 
Aug.  1  6 

29 

30 
Sept.    6 

18 
18 
i? 
17 
16 
16 
10 
13 

IO 

II 
9 
9 

6 

17 
16 

15 

IO 
IO 

15 

IO 
IO 

9 
9 
9 

9 

8 
8 
8 
8 

7 
8 

6 

7 
6 

6 

7 

6 
6 

14 
16 

14 
15 
15 
"4 

'3 

12 
12 
13 
'3 
IO 

9 

2410000+ 
4337-00 
4352.oo 
4364.92 
4372.92 
4381.88 

4395  •  83 
4460.67 
4462  .  63 
4478.67 
4489.71 
4511-63 
4519.63  | 

4664.50 

4736  •  96 
4761.92 
4785.88 
4804  .  67 
4813.67 
4816.88 
4832.67 
4844.67 
4877.60 
4889.66 
4897.60 

4902  .  60  1 

4918.56 
4930.56 
4934.56 
4946.56 
4952.54 
4962.58 

4967.54 
4974  •  50 
4981.52 
4985  •  50 

4996  .       ] 
5008  .  50 
5017-52 

5024.50 
5044  .  50 
5081.83 
5141-92 
5143-83 
5151.88 
5179.88 
5190.83 

5"99.79 

5221.75 
5226.75 
5248.79 
5261.79 

5262.67 
5269.63 

150 
150 
150 
150 

80 
80 

150 
150 
200 
150 
150 
150 
150 
150 
150 
150 
150 
150 
150 
40 

40 
40 
80 
40 
40 
40 
40 
40 
40 
150 
40 
150 

150 
"So 

275 

275 

460 
237 
350 

237 

237 
460 
460 

700 

237 
237 

6 
6 
6 
6 

12 
12 
12 
12 
12 
6 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

6 

6 

12 
12 
40 
40 
40 
40 

40 

40 
40 
40 

40 

40 
40 

v  not  seen  limit  a  

<I2.2 

<n.i 
<n.8 

<I2.2 

11.83 
10.83 

II  .21 
II  .42 
11.76 
12.03 
12.67 

12.68 

<I2.2 
<I2.2 
<I2.2 
<I2.3 
<I2.2 
<I2-3 
<I2.4 
<I2.5 
<I2.7 
<I2-4 
<  12.2 

"•33 

9.86 

7.83 
7.80 

7-93 
8.52 
8.46 
8.83 
8.83 
8.97 
9-'5 
9.14 

9-85 

10.15 
10.50 

10.78 
ii  .40 
12.74 

<*3 

14.4 

14.58 

good 
fair 
fair 
fair 
good 
good 
good 

good 
fair 
good 

fair 

5'8 
3 
68 
70 
86 

97 
119 

127 

+  '•43 
+  0.95 
+  0.61 
+  0.78 

+  0.74 

+  0-75 
+  0.85 

+  0.65 

D  not  seen  limit  /  

i)  not  seen  limit  1  4M  <  k  .  .  . 

1)2<J,  fSV  

29-6,  29.5  
37-5,  38.6,  34.5,  34.2 
33-5.  31-9,  36.4  
33.0,  32.4  
29-5,  28.4,  32.6  
27-5,  28.6  
24-1,  22.5  
23-1,  23-0  ) 
2-16  f 

29-5 
36.7 
33-9 
32.7 
30.2 
28.0 
23-3 
23-2 

jiv,  vie,  Dg  

/I-2D,  11I-2C  

d^-v,  c2-y.',  v$a  
d6v,  via  
03-41),  D2-3;y  
a4-5^,  "37.  l'm>t  y  
a$v  limit  V  

v  not  seen  limit  a  

v  not  seen  limit  a  

D  not  seen,  limit  i  <<*  

v  not  seen  limit  a  

fair 
good 
fair 
good 
good 
moon 
good 

good 

good 
good 
good 
moon 
good 
fair 
good 
good 
fair 
fair 

fair 
good 

fair 
poor 
fair 
fair 

poor 

505 
51° 
526 
9 
13 
25 
3i 
4i 
46 

53 
60 

64 

75 

87 
96 

103 
123 
1  60 

222 
230 

+  0.23 

-o-95 
-2.26 
-     93 
-    -75 
-    .16 

-    -34 
-    -17 
-    -27 
-    -30 
-    .26 
-    .36 
—  0.92 
—  0.89 
-0-75 

—  0.65 
-0.52 
-0.13 

o.o 

-o.4± 

11  not  seen  limit  2  <a  

D  not  seen  limit  2<Co  

i>  not  seen,  limit  4~5<a.  .  . 

v  not  seen,  limit  a  

i>4-5a,  -vg,  /3-4D  

T5g,  1)4^  k2V  fn2U 

32.1,  36.4,  31.0  

4i-4,38.5,39.9,39.9l 
48.4,  48.4,  48.4.  .  .  ) 
56.4,57.2  
56.4,  57-7  
56.4,  56.2,  56.3  

33-2 
43-5 
56.8 
57-i 
56.3 
52.4 
52.8 

50.5 
50.3 
49-3 
48.  i 

48.3 
44-8 

41.3 
39  o 

37-0 
32.7 

22.7 

D4-5n,  Ti2x,  vid  
DijM>;t:,  V2g  

VIOX,  D2~3£  

•viox,  vis,  v(  
1)6*  

Tl&x  i  ,  £411  

54.  4.    SI  2    . 

£51;,  1)4*  
£41),  vyc  

£5-6l>,  V2-3X  

£6-8i>,  vi-2x  
E6-8D,  i>2x  

X2—^V  

50.7,  50.4  
51.2,  49.4  
49.7,  48.9  
48.2,  47-9  
48.2,  48.4  
47  q  .  .                       .  .  ) 

X2-$V,  t'4«  

xffv,  nii>,  D5~6g  
n\v,  f3-4/,  i>4g  

n$v,  i)g,  V2-3/  

g4D,  J1-2V,  1)1-2*  

a6i>,  v3~4y,  limit  y  

43.9,  46.8  > 
40.4,  41.8,  41.9  
38.8,  38.0,  40.4  

37-8,  36.4,  37-0  
32.4,  33-0  
21.6,  23.5  

IMS  i  to  iiM<;c,  /*•  is  2"<y. 
i'  is  i  to  i  ^M  <  y,  }'3~  4^  .  .  . 

f-  seen,  but  nothing  near  i 
11  not  seen  limit  IM<^  .  . 

<2.0 

-0-5 
30 

-3-S 

<«4 

15-44 

15-08 
16.0 
<I5 
17-  o± 

<i5 

<I3 

moon 
fair 
fine 

278 

300 
305 

—  O.22 

—  1.  00 
-O.I± 

T  MO—  ITT  7T<i—  5D.  .  .  .  ) 

l/^'k  '  '  '  > 

i  -v  glimpsed,  not  steadily  held 
|T  is  iito2"<<",  andiw<.4 

) 

fair 

moon 
moon 

340 

+  o.4± 

) 

CHAPTER   XI. — V   UELPHINI. 


155 


TABLE  95. — 7458  V  DELPHINI.    VISUAL  OBSBRVATIONS  OP  THE  VARIABLE. — Continued. 


No. 

Date. 

i4 

a 

1 
fi 

| 

•< 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing. 

t. 

4  Mag. 

Month 
and  Day. 

Hour 

C.  S.  T. 

Julian 
Day 
G.  M.  T. 

Steps. 

Mag. 

IOO 

1OI 

1  02 

103 

104 

105 

106 
107 
108 

109 

IIO 
III 

112 

"3 

114 

"5 

116 

"7 
118 
119 
1  20 

121 
122 
123 
124 

125 
126 

127 
128 

I2Q 

130 
IS' 

132 

'33 

'34 
135 
136 
137 
138 
139 
140 

MI 

142 

'43 

19  o 
Sept.  3 
Oct.     4 

16 
Dec.   1  1 
'9 

1901 
Oct.    18 
Nov.     i 

4 
Dec.   2! 

1902 
Mar.  28 

Apr.    1  2 
May     8 
29 

July     3 
Sept.     7 

26 

1903 

Apr.     3 
July   24 
Sept.  17 
Oct.      9 
25 

1904 
July  31 
Aug.     3 
6 

Oct.     8 

Nov.  30 

1905 
Jan.      3 
Mar.   1  2 

Apr.     4 

II 
30 
May   22 

June     4 

13 
26 
July   23 
Aug.     9 
ii 
28 
Sept.  17 
Oct.      i 

20 

Dec.   30 

12 
IO 

9 
6 
6 

8 
8 

9 
6 

15 
15 
13 

12 

IO 
10 

II 

15 
10 

8 

12 

9 

12 
II 
II 

7 

7 
i? 
16 

16 
15 

14 

14 

14 
1  1 

IO 

9 

10 

9 
8 
IO 

7 
6 

2410000  + 
5276.75 
5297-67 

5309-63 

5365  50 
5373-50 

5676.58 
5690.58 
5693.63 
5740.50 

5837-88 
5852.88 
5878.79 
5899-75 

5934-67 
6000.67 

6019.63 

6208  .  88 
6320.67 
6375-58 
6397 
6413 

6693.75 
6697.63 
6700.75 
6700.71 
6762.71 
6815.54 

6849.54 
6917.94 

6940.92  < 

6947.92 
6966.  88 
6988.83  • 

7001.83  - 

7010.83 
7023.71 
7050.67 
7067.63 
7069.67 
7086.63 
7106.56 
7120.67 

7139.54 
7210.50 

237 
237 
460 

150 
150 

130 
275 
460 
350 

237 
237 
460 

237 
so 

237 

237 
237 
so 

150 

67 

237 
40 

237 
450 
750 
750 

750 

237 
450 
250 
250 
450 
237 
300 

237 
40 

40 
150 
237 
so 

237 

40 
40 
40 

6 
6 

12 
12 
40 
40 

40 
40 
40 
40 
12 
24 
40 

40 
40 

6 

12 
12 

6 
12 

18 

12 
40 

6 

40 
40 
40 
40 

40 

40 
40 
40 
40 
40 
40 

12 
40 

6 

12 

6 
6 

40 

12 
40 

<I5 
<H 
<i6 

<I2.8 
<I2.5 

<I3 
<i3-5 
<i5-i 
OS 

<i3-9 
<i6.7 

15    20 

14.66 

<U 

10.4 

10.29 

14.90 
<«4 

<I2.6 

<I3 

<«3 

<I2 

<i3 

15.00 

<I4 
<J5 

<I2.3 

<i5 
<i4.o 

14.86 

14-59 
14.  16 

13-57 

13-36 

12.79 
12.60 
10.83 
10.15 
10-35 

1O.2I 
IO.62 
10.98 
II-50 
»3-57 

moon 
moon 

good 

•v  not  seen,  limit  tu'  or  4<y 
(v  suspected,  not  held.limit 

(     !*</*. 

v  not  seen   limit  3<fl 

v  not  seen,  limit  y     .    . 

moon 
good 
poor 
fair 

moon 
good 
fair 
fair 

428 
449 

—  0.06 
+  0.43 

v  not  seen,  limit  3<y.  . 

v  not  seen   limit  i-2<7T 

it  not  seen   limit  TT 

•y  not  seen   limit  6<y 

f  v  not  seen,  limit  4<Aor 
\    2-3<;r 
<Pyi,  l)2i>,  l>-2i!,  TIT;  
f  f3-4/x,  «i.u,  y8-iav±  .... 
\v  is  i  ".36  <y,  photometer 
v  not  seen   y  limit 

i 

V 

\ 

1.5,  1.5,  o.o,  3.0  

}.. 

i5 
5-5 

/ 

photograph  plate  . 

poor 
poor 

poor 
poor 
good 

21 
40 

229 

+  o.8± 
+  0.31 

+  0.34 

<v<x  by  1.09=10.37.  .  .  ) 
\v<d  by  0.91  =  10.21  .  ..  .| 

111-2,'*,  VI-27;  ±  

v  not  seen,  limit  i>"<y.  .  . 

3-5,  5-5  

4-5 

v  not  seen,  limit  4<Cfl 

v  not  seen    limit  y 

v  not  seen,  limit  a 

v  not  seen   limit  y 

y>4i>,  11411,  i>3f>,  114*  
photographs,   Nos  94    95 

0.5,  2.0,  6.5,  8.0.  ... 

3-3 

good 
good 
fair 
good 

fair 
poor 

fair 

fair 
fair 
fair 

fair 

fair 
good 
good 
good 
fair 
good 
dull 
fair 
good 
good 

191 

436 

440 
458 
480 

493 
502 
5'5 
13 
30 
32 
49 
69 
83 
102 

1/3 

+  0.14 

—  0.06 

—  o.  19 

+  0.36 
+  0.92 

+  '•35 
+  I-34 

+  2.01 

+  1.13 
+0.26 

o.oc 
o.oo 
+  0.05 

-t-O.IO 

+  °  44 

<p$v  or  /•*,  V  or  /•i3,0 

1}  not  seen   limit  i   2  <0 

¥111  or  I1-,  v  or  f*ip 

<f2V,    V2f,    l>4/i  

fiv,  »3,°,  V3H  
/  v6,'*,  VI<P,  vi*  
\  a>8v  

2.5,  5-5,  6.0  
3-5,  6.5,  5-0  
8.0,  8.5,  5.0  \ 
7.5  / 

4.7l 
5-oi 

7-2 

ii.  8 
16.5 

18.2 

22.6 
24.0 

36.5 
40.9 

W,  v5Vi  *8/*  
1/3—  471,   aiiv,  i>6(u'  
yyu,    viw  
i>i-2y,   VI-2UI  

yi—  2V,    1I1—2U)  

16.0,  9.5,  10.0  
16.5,  14.0,  16.0.  .  .  ( 
17.0,  18.0  ) 
21.5,  16.5  \ 
i8.s,  i6.s  / 

V2y,  04-50)  
<J4T,  T4-5r  

V2f 

22.  0,  23.1  

23.6,  24.5  

lid—  8g,  kiv,  vim  
photographs,  Nos.  211,  212 
kiv,  113111,  i>5g  

43-4.  39.2(  41.9  

39-2,  43.9,  41.4  
(32.9),  37-4,  38.5  •• 
35-4-35.5  
32.5.  30.9,  32.6  
16.0,  17.0  

40.4 

37-8 
35-4 
3«  9 
16.5 

SIT,  Tiif  
J2ii,  vc,  -v$a  
yqv,  vo-iiu,  v$<r  

J56 


RESEARCHES  IN   STELLAR   PHOTOMETRY. 


\      Ol       In 


<£ 


to     flb 


t/1 

^ 

» 

7-^55  V  DELPHI  Nl 

MAR.  1900  SEPT.  MAR.  1901  SEPT.  MAR.  1902  SEPT.  MAR.  1903  SEPT.  MAR.  1904  SEPT. 
^/C>.  5(700  52(70  5-?O(3  5600  5800  5000  6<?00  6<?00  6600  650O 

S 

X 

X1 

/ 

X* 

/ 

« 

/ 

7 

< 

< 

\ 

\ 
s 

N. 

<< 

—  — 

X 

""l 
/ 

S 

X 
X 

x' 

X 

/ 

/ 

s 
/ 

< 

- 

/ 
/ 
/ 

1 

< 

\ 
\ 

< 

X^ 

< 

^~ 

— 

—  - 

"*1 

X 

x' 

/ 

X 

/ 

s' 
s 

/ 

/ 
/ 

A 

1 

1 
\ 
\ 

< 

^  t 

-- 

--- 

-- 

-~- 

^ 

•^ 

f 

X 

X 

/ 

S 

X 
X 

X 

/• 

y' 

s 

O5 


§tn 
n 
"D 


65 


en 

,    rn 
Co  -o 


in 

n 


o 


$5 
§S 

in 
ri 


-(x 
I 


5 

v  <O 
CD 


On 


h 

i 

o 


33 


ocn 
O  n 


FIG.  32.— LIGHT-CURVE  OF  V  DKLPHINI. 


CHAPTER  XI. — V  DELPHINI. 

TABLE  96. — 7458  V  DELPHINI.     MEAN  MAGNITUDES  PROM  44^  DAY  GROUPS. 


157 


Group 
I.  D  . 

Vo  

i 

44 

2 
88 

3 
132 

4 
176 

5 
220 

6 
265 

7 
3°9 

8 
353 

9 
397 

10 

441 

ii 

485 

12 
529 

3334 
3863 

4392 
4921  • 

5450  i 
5979  ' 
6508  - 

7037  ' 
Means  ' 

f        t 
M 

1     JM 
L   No. 

(  - 

|     JM 
L   No. 

r    t 

1       M 
]     JM 
L    No. 

r  '  < 

M 

JM 

L    No. 

r   M' 

JM 
No. 

f       M' 
JM 
No. 

r        t 
M 
JM 
No. 

1 
M 

4M 

k    No. 

f      J 

JM 
,    No. 

22 
10.98 

+  1.19 
3 

24 
9.60 

—  O.2O 

8 

3 
10.83 

+  0.95 
i 

24 
8.31 
-1.47 
5 

66 
11.81 
+  1.23 

5 

60 
10.24 
-0.17 

2 

75 
11.46 
+  0.71 
3 

64 
9-35 
-i.  17 
6 

98 
13-35 
4-1.06 

2 

5«7 
10.80 
4-0.32 
3 

5l8 

11.83 

+  I-43 

i 

514 
9.67 
-0.99 
3 

114 
12.46 
+  0.75 

3 

107 
10.89 
—  0.64 
3 

1  60 
12.74 
-0.13 
i 

226 
14-  3± 

-0.2± 

2 

294 
15-49 
-0.44 
3 

340 
17.  o± 
4-o.  4± 
i 

428 
15.20 
—  0.06 

i 

449 
14.66 

4-0.43 

i 

3° 
10.34 
+  0.56 

2 

229 

14.90 
+  0.34 
I 

191 

15.  °± 
4-i-4± 
i 

429 

14-77 
-0.39 
3 

23 
9.62 
-0.17 
19 

66 
10.63 
+  0.06 
16 

107 
11.85 
4-0.31 
8 

160 
12.74 
-0.13 
i 

191 

i5-°± 
4-i.  4± 
i 

227 
I4-50 
—  O.O2 

3 

294 

15-49 
-0.44 

3 

34° 
17.  o± 
4-0.  4± 
i 

429 
14.88 
-0.31 
4 

449 
14.66 
+  0.43 
I 

5i6 
10.46 
—  0.08 

7 

MAGNITUDE-CURVE. 

Fig.  31  gives  a  graphic  view  of  the  relation  between  the  visual  and  photo- 
metric magnitudes.  From  this  curve  are  taken  the  magnitudes  of  the  stars  not 
measured  photometrically,  and  also  the  magnitude  of  the  variable.  The  devia- 
tion of  the  star  /  from  the  curve  seems  greater  than  is  allowable ;  this  is  explained 
by  the  fact  that  its  place  in  the  light  scale  depends  on  but  one  comparison  with 
the  variable,  and  therefore  the  effect  of  an  error  is  slight. 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


too 


200 


DAYS 

3OO 


+OO 


SOO 


60O 


10 


II 


7458V  DELPHI  Nl 
Max.'  536  <* 


u 
o 

t/3 
I 


IS 


n 


FIG.  33. — MEAN  LIGHT-CURVE  FOR  V  DEUPHINI. 
LIGHT-CURVE. 

Fig.  32  shows  the  star's  variations  from  June,  1894,  to  August,  1904,  the 
parts  of  the  curve  determined  by  the  observations  being  drawn  full,  the  parts 
assumed,  with  a  broken  line.  When  the  variable  was  invisible  the  limit  of  vision 
is  indicated  by  the  point  of  the  V-shaped  characters.  It  will  be  seen  that  the 
observations  fix  definitely  the  number  of  maxima  possible  during  this  interval, 
determine  the  time  of  maximum  for  epochs  4,  5,  and  6,  with  considerable  certainty, 
and  of  epochs  3  and  8  less  definitely,  and  show  that  the  magnitude  at  minimum 
is  in  the  neighborhood  of  17. 


CHAPTER   XI.  —  V  DELPHINI.  159 

The  striking  characteristics  of  the  star's  variation  are  its  great  range,  but 
little  less  than  10  magnitudes,  and  its  rapid  rise  to  maximum,  best  shown  at 
epoch  6.  The  curve  at  maximum  is  usually  quite  sharp,  though  this  is  not  con- 
firmed by  the  observations  of  Reed  at  Harvard  in  1891,  published  in  Astronomical 
Journal,  13,  63.  Further  reference  to  these  observations  will  be  made  later. 
The  shape  of  the  curve  near  minimum  can  be  inferred  by  combining  the  observa- 
tions on  the  descending  branch  of  the  curve  following  maximum  6  in  1900,  and 
those  on  the  ascending  branch  preceding  maximum  8  in  1902.  Combining 
these  observations  with  the  limit  of  vision  when  the  star  was  not  seen,  the  curve 
at  minimum  is  fixed  very  nearly  as  drawn. 

PERIOD   OF   VARIATION. 

The  elements  of  maximum  given  by  Chandler  in  his  Third  Catalogue  and 
retained  in  his  "Revised  Elements,"  published  in  1904 

1890  December  20  (2411722)  +  54odE. 

are  based  on  six  maxima  between  1890  and  1899,  fitting  the  first  five  maxima 
very  well,  but  requiring  a  correction  of  -  34  days  for  epoch  6,  and  about  -  80 
days  at  epoch  9.  The  observations  now  available  are  represented  better  by  the 

elements, 

1891  January  14  (2411747) 


This  was  obtained  by  using  only  the  best  observed  maxima,  2,  4,  and  6,  and 
shortening  the  period  thus  obtained  2  days  on  account  of  the  last  maximum 
in  the  light  -curve,  No.  9. 

In  this  connection  two  sets  of  observations  require  separate  consideration. 
First,  Mrs.  Fleming's  measures  from  the  photographs,  published  in  Astronomische 
Nachrichten,\27,  5,  showing  that  the  star  was  invisible,  less  than  loth  magnitude, 
on  six  dates  from  June  30  to  October  28,  1890,  and  photographically  9.3  magni- 
tude, November  28;  8.6  on  December  19;  9.0  December  20,  and  8.7  on  December 
22.  Considering  the  small  number  and  range  on  these  plates  it  is  thought  that 
no  violence  is  done  to  them  by  assuming  the  date  of  maximum  to  be  as  late  as 
January  14.  Second,  a  set  of  observations  made  at  Harvard  by  W.  M.  Reed, 
and  published  in  Astronomical  Journal  13,  63,  are  not  in  accord  with  the  above 
elements  and  mean  light-curve.  They  are  given  in  Table  97,  with  the  addition 
of  three  columns  giving  respectively  the  Julian  day,  the  number  of  days  after 
the  preceding  maximum  as  calculated  by  the  foregoing  elements,  and  the  cor- 
responding magnitude  from  the  mean  light-curve. 


i6o 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABLE  97. 


Reed. 

Mag. 

.  D. 

from 

Date. 

Mag. 

curve. 

1891  May  28 

9.2 

1881 

+  134 

12.6 

June  9 

9-i 

i893 

+  146 

12.9 

June  15 

9.0 

1899 

+  152 

13.0 

July  9 

9.0 

1923 

+  176 

13-5 

July  27 

9.2 

1941 

+  '94 

13-9 

Aug.  20 

Sept.  2 

9-4 

1978 

+  231 

14.6 

1892  Nov.  3 

9.0 

2406 

+  130 

12.6 

If  Chandler's  elements  are  used  the  intervals  after  maxima  will  be  still  greater, 
so  that  a  considerable  change  in  period  or  form  of  curve  must  be  assumed  to 
explain  the  discrepancy,  unless  the  star  was  misidentified. 

NOTE. — The  well  observed  maximum  of  epoch  10,  completed  since  the  above 
was  written,  gives  a  correction  to  the  ephemeris  of  +34  days.  Using  the  three 
best  determined  maxima,  the  period  between  epochs  4  and  6  is  524  days,  between 
6  and  10  it  is  539  days,  giving  a  mean  period  of  533  days,  and  indicating  a  secon- 
dary term  in  the  elements,  which  will  require  further  observations  to  definitely  fix. 

TABUS  98. — 7458  V  DSUPHINI.     OBSERVED  MAXIMA.  AND  MINIMA. 

Elements  of  maximum.     1891  Jan.  14  (J.  D  2411747H529'1  E.     M-m=16I'>. 


MAXIMA. 

MINIMA. 

I 

w 

Date. 

Mag. 

Corr. 

Wt. 

W 

Date. 

Mag. 

Corr. 

Wt. 

Calendar. 

J.  D. 

H. 

p. 

Calendar. 

J.  D. 

H. 

P. 

3 
4 
5 
6 

7 
8 

9 

IO 

1  895  May    1  5 
1896  Nov.  16 
1898  May      5 
1  899  Oct.      i 
1901  Mar.    16 
1902  Aug.  22 
1  904  Jan.    20 
1905  Aug.  1  8 

3329 
3880 

44'5 
4929 

5455 
5984 
6500 
7076 

10.50 
9.40 

10.76 

9.66 

me 
me 
8.08 
10.3 
me 
10.36 

—  IO 
+  12 

+  18 
+   3 
+   5 
o 

-13 

+  34 

6 
19 

IO 

24 

4 
i 
20 

4 
5 
7 
8 

9 

IO 

1896  May   30 
1897  Nov.   1  8 
1900  Sept.  27 
1902  Feb.  26 
1903  Aug.  23 
1905  Jan.      4 

371° 

4247 
5290 
5807 
f>350 
6850 

17.0 

me 
me 

17-3 
me 
me 
me 

+  3 
+  11 
-  4 
-16 

—  2 

-35 

i 
i 
8 

2 
2 
2 

7.80 

IO.O 

IO.  IO 

CHAPTER  XII. 


R.  A. 


85 1 8  Z  CASSIOPEIA, 
jm  395.9;   Dec.  +  56°  i'  33"  (1900). 


This  variable  was  discovered  by  Anderson  in  1898  and  observations  began 
in  January,  1899.  The  field  was  measured  with  the  micrometer  on  the  6-inch 
in  January  and  February,  1899,  but  as  the  approximate  place  given  for  the  star 
fell  nearer  to  r  than  to  the  true  place  of  the  variable,  that  star  was  marked  as 
the  variable  in  the  finding  chart  published  by  the  writer  in  Popular  Astronomy, 
7,  94.  The  place  of  the  variable  given  above  was  measured  with  the  6-inch  from 
the  stars  a  and  b,  which  are  given  in  the  Helsingfors-Gotha  A.  G.  catalogue. 
The  stars  b,  d,  n,  and  x  were  connected  with  the  variable  in  January,  1900,  with 
the  40-inch. 

My  experience  with  this  field  is  a  good  illustration  of  the  advantage  of  using 
several  standard  magnitude  stars.  The  list  selected  included  B.  D.  +54°  3033, 
but  after  the  photometer  measures  were  completed  it  was  found  that  the  star  had 
been  misidentified,  3036  being  measured  instead.  The  measures  were  therefore 
reduced  with  the  other  two  stars  as  standards,  without  much  loss  in  accuracy. 

A  few  of  the  faint  comparison  stars  are  so  close  to  the  variable  that  the 
scale  used  for  the  other  charts  would  be  too  small;  this  chart  is  therefore  repro- 
duced on  nearly  double  the  usual  scale. 

TABLE  99. — 8518  Z  CASSIOPEIA.    STANDARD  MAGNITUDE  STARS. 


Star. 

B.  D.  No. 

1900. 

Color 
P.  DM. 

Magnitude. 

Residuals. 

R.  A. 

Dec. 

Catalogue. 

Measured. 

From  Cats. 

3 
Nights 
inter 
se. 

H.  C.  O. 

P.  DM. 

H. 

P. 

H. 

P. 

A 
D 

o 

+  55  3010 
+  55  2990 

h    m     s 
23  39  56 
23  32  26 

O              / 

+  55  14-7 
+  55  '9-4 

WG 
G 

6.48 
7-5i 

6.58 
7.20 

6.76 
7.24 

6.65 
7.13 

+  28 
-27 

+  7 
-7 

±4 
±5 

7.00 

6.89 

7.00 

6.89 

±28 

±7 

±4 

TABLE  100. — COMPARISON  STARS  IN  B.  D.  CATALOGUE. 


B.  D. 

1855- 

Star. 

No. 

Mag. 

R.  A. 

Dec. 

O 

h  m  s 

o 

b 

+  55  3007 

9.2 

23  37  5 

+  55  5°  -o 

a 

+  55  30" 

8.6 

23  37  47 

+  55  39-9 

161 


162 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABLE  101. — COMPARISON  STARS  FOR  Z  CASSIOPELE  (IN  ORDER  OF  RIGHT  ASCENSION). 


Coordinates  from  Variable. 

Magnitude. 

Star. 

Light 
Scale, 

Measured. 

From  Curve. 

R.  A. 

Dec. 

Steps. 

H. 

P. 

H. 

P. 

h 

n 

-276 

-32-9 

H 

+     3 

37-0 

10-75 

10.64 

b 

—  208 

—  24.8 

+  200 

44.1 

9-79 

9.68 

f 

-188 

—  22.4 

—  420 

1 

g 

-182 

-21.7 

-3" 

27-5 

11.97 

11.86 

X 

-"7 

-13  9 

+   97 

17.1 

I3-38 

13.27 

1 

—   92 

—  ii  .0 

—  188 

r 

-   89 

—  10.6 

-182 

3i-5 

"-45 

"•34 

e 

-   88 

-10.5 

-137 

23.1 

12.25 

12.  14 

k 

-    78 

-  9-3 

-239 

21.6 

12.99 

12.88 

s 

-   47 

-   5-6 

-      8 

6.0 

14-32 

14.21 

o 

-   23 

-   2.7 

-    83 

99 

13  96 

13-85 

n 

-    17 

—     2.O 

-     9 

8.0 

13.96 

13-85 

t 

+      3 

+     0.4 

+   40 

I  .0 

14.88 

'4-77 

u 

+     4 

+  a.  5 

+     22 

i-5 

14.82 

14.71 

w 

+    17 

+     2.0 

-     17 

o.o 

15.00 

14.89 

g 

+   28 

+   3-3 

+    57 

II.  O 

»3-72 

13.61 

d 

+   40 

+   4.8 

+  121 

36.4 

10.94 

10.83 

P 

+  40 

+   4.8 

+   37 

IO.O 

13.64 

13-53 

a 

+  139 

+  16.6 

-448 

8.32 

8.21 

TABLE  102. — 8518  Z  CASSIOPELB.    PHOTOMETER  MEASURES  OF  COMPARISON  STARS. 


1904  September  5.                                              6-INCH.                                          Good,  a  little  dull. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

h    m 

o 

20  39 

31 

Dai 

13.3   12.8  13.4 

I3-I7 

12.95 

0.63 

7-94 

7-83 

E 

14-3  '3  7  15  o 

'4-33 

14-33 

0.84 

8-15 

8.04 

Ad\ 

10.0     9.0     9.9 

9  63 

9-55 

0.24 

7-55 

7-44 

a 

17.0  15.8  15.9 

16.23 

16.62 

1.17 

8.48 

8-37 

h 

37-5  39-9  38-2 

38.53 

37-82 

3-65 

10.96 

10.85 

30 

b 

24-5  25.1   25.0 

24.87 

25-22 

2-15 

9.46 

9  35 

d 

39-5  39-9  39-8 

39-73 

39-78 

3.82 

"-13 

ii  .02 

d 

40.0  39.  7  39.8 

39-83 

b 

24  .9    2S  .  0    2$    Q 

2?    57 

h 

77  .  l    77  .  7    7.6  .  Q 

77  .  IO 

a 

17.2   17.0  16.8 

17  .  OO 

Aai 

9.2     9.3     9.9 

9-47 

E 

14..  1    14.8    17    O 

I  A    77 

20  59 

28 

£>„, 

12.2    12.9    13.  I 

12-73 

STELLAR   PHOTOMETRY. 


N 

OS 


PLATE   12. 


-305 


* 


— -I- to' 


•u 

®. 

W  1 1      *  S 


•V 


5' 


a,' 


f. 

.  • 


Scale,  i  mm  =  7".  2. 


1902  January 


R-  A- 


8518  Z  CASSIOPEIA. 

39m  39s-9-     Dec.  +  56°  i'  33",  1900. 


CHAPTER   XII. — Z   CASSIOPEIA.  163 

TABLE  102. — 8518  Z  CASSIOPEIA.     PHOTOMETER  MEASURES  OF  COMPARISON  STARS.— Continued. 


1904  October  i.                                                     6-INCH. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

h   m 
22  32 

22    52 

O 

'7 
15 

E 

Aai 
Dai 
a 
d 
b 
h 
h 
b 
d 
a 

Dal 
A  01 
Eat 
E 

14.7  15.3  14.7 
9.8     9.9     9.0 
14.0  13.3  13.7 

15-3   '5-9  15-7 
38.2  38.3  38.1 
28.4  27.9  28.  I 
37-9  38.2  38.6 
38.3  38.7  39-0 
28.2  29.1  28.3 
38.9  39-1  39-o 
16.8   16.3   16.3 
14.2   13.8   13.7 
9.9  10.  i     9.1 

2O.9    21  .3    22.  O 

13-4  H  -o  13-3 

14.90 
9-57 
13-67 
15-63 
38.20 
28.13 
38.23 
38.67 

28.53 
39-00 
16.47 
13.90 
9.70 

21  .40 
13-57 

14.24 
9.64 

13-79 
16.05 
38.60 
28.33 
38.45 

0.82 
0.25 
0.76 
1.09 

3-71 
2.49 
3-70 

8.07 
7-50 
8.01 

8-34 
10.96 

9-74 
10-95 

7.96 
7-39 
7.90 
8.23 
10.85 
9-63 
10.84 

1904  October  5.                                                                                                             Floating  clouds. 

21    2O 

21   37 

27 
25 

A., 

Eat 
Dai 
a 
d 
b 
h 
h 
b 
d 
a 

8.2     8.2     7.5 
18.4  17.8  18.6 

12.2     12.3     12.  O 
13-4    13-5     14    2 
38.3    38.9    38.2 
23-5    23.3    23.9 
36.1    36.0    35.6 
36.6    36.1    36.3 
24.7    25.2    25.8 

37-8  37  4  38  o 
13  3   13-4  '3-3 

7-97 
18.27 
12.17 
13-70 
38.47 
23-57 
35.90 
36.33 
25-23 
37-73 
13-33 

O.  12 
1.38 
0.52 
0.72 
3.67 
2.O7 
3-42 

7-55 
8.81 

7-95 
8.15 

II  .  IO 

9  50 
10.85 

7-44 
8.70 
7.84 
8.04 
10.99 
9-39 
10.74 

13-52 
38.10 
24.40 
36.12 

1904  October  27.                                                                                                                             Fine. 

20  34 

20  57 

33 
29 

Dai 

E 
Aai 

a 
d 
b 
h 
h 
b 
d 
a 
Aai 
Eat 
E 

Dai 
Dai 

15.2   14.9  14.9 
13.0  13.  i   13.0 
8.7     9.4     8.8 
14.7   14.9  15.1 
38.6  39.2  39.3 
24.3  25.2  24.9 
38.2  37.7  37.0 
37-7  37-6  37.8 
27.7  27.1   27.2 

39-5  39-7  39-2 
15.1   14.6  15.1 
9.2     9.0    9.0 

20.0    19.3    19.7 

12.9  '3-3  13  o 

12.4    13.2    12.9 
14.2    14.0    14.  I 

15.00 
13  03 
8.93 
14.90 

39-03 
24.80 

37.63 
37.70 
27-33 
39-47 
14-93 
9.07 
19.67 
13-07 
13-47 

14.24 

13-05 
9.00 
14.92 

39-25 
26.07 
37.67 

0.82 
0.65 

0.18 
0-93 

3-77 
2.25 

3-63 

8.07 
7.90 

7-43 
8.18 
ii  .02 
9-50 
10.88 

7.96 
7-79 
7-32 
8.07 
10.91 
9  39 
10.77 

1-55 

8.80 

8.69 

164 


RESEARCHES   IN  STELLAR  PHOTOMETRY. 


TABLE  102. — 8518  Z  CASSIOPEIA.     PHOTOMETER  MEASURES  OP  COMPARISON  STARS.— Continued. 


1904  September  n.                                          12-INCH.                                                               Good. 

Sidereal 
Time. 

Zen. 

Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

h    m 
19  26 

19  50 

0 

4' 
38 

flai 

k 

e 

g 
•v 
d 
b 
h 
h 
b 
d 

V 

g 
e 
k 
<2ai 

13-3  13-4  13-1 
47-3  49-3  48-8 
40.  i  41  .0  40.9 
37-7  38.2  38.3 
49.1  47.4  47.2 

3O.O    28.8    29.  2 

18.0   18.8   18.2 
26.1   26.5  27.3 
27.5   27.7  27.0 
18.7  19.0  18.0 
30.4  30.0  30.1 
47.8  48.1  48.8 
39-3  39-0  39.0 
41  .0  41  .0  40.4 

46-5  47-7  48.3 
13.5  13.6  14.1 

I3-27 
48.47 
40.67 
38.06 
47.90 
29.67 

18-33 
26.63 
27-40 
i8.57 
30.17 
48.23 
39.10 
40.80 
47-50 
13-73 

13-50 
47-99 
40.74 
38.58 
48.07 
29-92 
18.45 
27.02 

0.85 
4.62 
3-86 
3.61 

4-63 
2.64 
1.50 
2-38 

9.17 
12.94 
12.  18 
"•93 
J2.95 
10.96 
9.82 
10.70 

9.06 
12.83 
12.07 
ii  .82 
12.84 
10.85 
9-7' 
10.59 

1904  November  2.                                                                                          Fair  to  good,  quiet,  dull. 

20  36 
20  56 

3i 
29 

a 
d 
b 
h 
e 
k 
S 

! 

e 
h 
b 
d 
a 

12.  I     II  .2     12.  O 

35-o  35.0  35.0 

24.3    22.9    23.3 

32-7    31-5    32-5 
47.7    48.6    47.2 

57-7  59-7  57-3 
43-3  44-o  43.8 
44.8  44.0  44.3 
59-2  57-8  59-9 
46  .  1  45  .  2  46  .  8 
34-0  33-o  31.8 
23.2  23.6  23.2 
35-0  34.8  34.2 
12.3  11.5  u.i 

11.77 
35-00 
23-50 
32.23 
47-83 
58.23 
43-70 
44-37 
58.97 
46.03 

32.93 
23-33 
34-67 
11.63 

11.70 

34-84 
23.42 
32-58 
46.93 
58.60 
44.04 

0.63 
3.18 
2.06 
2-93 
4-51 
5-43 
4.22 

8.38 
10.93 
9.81 
10.68 

12.  26 
13.18 
11.97 

8.27 
10.82 
9.70 
10.57 
12.15 
13-07 
U.86 

1904  November  3.                                                                                   Twilight  at  beginning,  good. 

20  37 

20   56 

32 
29 

a 
d 
b 
h 
e 
k 
g 
g 
k 
e 
h 
b 
d 
a 

Oai 

7.0     8.1      7.2 
32.3  32.1   32.1 
19.9   19.3   19.6 
32.8  31.1   32.1 
44.8  44.9  45.4 
49-5  49-6  49.7 
41.8  41.8  42.3 
41.5  42.0  42.2 
51.6  51.3  50.7 
45-5  43-6  44.7 
31.0  32.0  32.2 
19.9  21.2  20.3 
33-3  32-6  32.1 
6.0     8.1     7.2 
14-7  15-2   15.1 

7-43 
32-17 
19.60 
32.00 
45-03 
49.60 

41-97 
41.90 

51    20 
44.60 

31-73 
20.47 
32.67 
7.10 
15.00 

7-27 
32-42 
20.04 
31-87 
44.82 
50.40 
41.94 

0.23 
2.90 
1.72 
2.85 
4-30 
4.84 
4.00 

8.25 
IO.92 

9-74 
10.87 
12.32 
12.86 

12.  02 

8.14 
10.81 

9-63 
10.76 

12.21 

12-75 
II  .91 

CHAPTER  XII. — Z   CASSIOPEIA.  165 

TABLE  102. — 8518  Z  CASSIOPEIA.    PHOTOMETER  MEASURES  OF  COMPARISON  STARS. — Continued. 


1900  July  12.                                         40-INCH,  WEDGE  II.                                                       Moon. 

Sidereal 
Time. 

Zen. 

Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

h   m 

21 

o 

d 

X 

s 
e 

0 

a 
k 

1 
y. 

h 

11.2   16.0  14.0  15.2 

34-4  3i-8  32-9  32-7 
45.1  44.0  44.9  44.2 
26.0  24.7  24.8  23.  i 

37  5   •    • 

14.  10 
32.95 
44-55 
24.65 
37-5 
35-20 
28.48 

34-95 
30.60 
11.38 

0.56 
3-07 
4.46 

2.  2O 
3-65 
3-4' 
2.7O 
3-38 

10.87 
13-38 
14-77 
12.51 
13.96 
13-72 
13.01 
>3  69 

10.76 
I3.27 
14.66 
I2.4O 

13.85 
I3.6l 
I2.9O 

I3.58 

31-78 

34-5  35-o  33.9  37.4 
26.7  29.9  28.3  29.0 

34-i   35-3  35-4  35-O 
30.2  30.3  31.0  30.9 
10.9  12.8  ii  ,o  10.8 

0.23 

10.54 

10.34 

1900  October  24.                                                   WEDGE  II.                                            Seeing  variable. 

2    15 

b 
d 
? 
P 

V 

n 
e 
k 
g 

e 
n 

V 

P 
I 

15.0  17.1    15.7 
28.2  27.7  28.7 

54-5  53-3  53-5 
55  o  53.1  55.0 
53-o  55-3  5i-2 
58-3  58.1   57-2 
35-8  37.7  37.9 
44-2  44-9  43-6 
37-2  37-8  37.8 
37-8  36-7  36-0 
43-5  43-8  44-3 
35  o  37.0  37.2 

54-2  55-9  56.7 
50  .  o  49  o  51.2 
50.2  52.1   51.1 
49  9  52  4  50.0 
24.3  27.2  28.2 

<5-93 
28.20 

53-77 
54-37 
53-17 
57.87 
37-13 
44.23 
37.60 
36.83 

43.87 
36.40 
55-60 
50.07 
5i-i3 
50-77 
26.57 

0.83 
2.56 
5-13 
5-18 

5-io 
5-50 
3-57 
4.40 
3-62 

9-37 

II  .  IO 

13-67 
13-72 
13  64 
14.04 

12.  II 
12.94 
12.  16 

'  9.26 
10.99 
I3.56 
I3.6I 
13-53 
13-93 
12.  OO 
12.83 
12.05 

27-39 
52.27 

52-75 
51.62 

56-74 
36.77 
44-05 
37.22 

1905  January  3.                                                   WEDGE  v.                                                         Good. 

3     o 

e 
n 
•v 
P 
1 
9 
P 
v 
n 
e 
k 
g 

24.3  24.8  25.9 
31-9  33  o  31.6 
26.0  27.8  27.3 
41.7  41.7  41.5 
55-7  56.4  57-4 
38.7  37-9  37-3 
39-4  39-3  40.6 
39-5  40.0  39.1 
38.1   38.3  38.0 
54.2  56.8  57.8 
41.2  39.  i  40.8 
27-0  25.5  25.7 
30.0  29.9  29.8 

2O.  2    21.2    22.2 

25.00 

32.17 
27.03 

41-63 
56-50 
37-97 
39-77 
39-53 
38-13 
56.27 

40.37 
26.07 
29.90 

21  .20 

23.10 
31-04 
26.55 
41  .00 
56.38 
38.05 
39-65 

2.04 

2.77 
2-33 
3-89 
5-31 
3-56 
3-74 

12.  O6 
12.79 
12.35 
13.91 
15.33 
I3-58 
I3-/6 

ii   95 
12.68 
12.24 
13.80 
15.22 
'3-47 
13-65 

166  RESEARCHES   IN ^STELLAR   PHOTOMETRY. 

TABLE  102.— 8518  Z  CASSIOPEIA.    PHOTOMETER  MEASURES  OP  COMPARISON  STARS. — Continued. 


1905  January  7.                                                     WEDGE  V.                                          Clear,  unsteady. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

h     m 

0 

g 

25-0  25.5  25.4 

25-30 

24.90 

2.19 

12.08 

11.97 

k 

31-5  32-7  32-8 

32.33 

32.62 

2-93 

12.82 

12.71 

e 

28.7  28.9  29.7 

29.  10 

27.52 

2.42 

12.31 

12.20 

n 

41  .8  42.9  42.0 

42.23 

42.46 

4-05 

13-94 

13-83 

•v 

53-8  54-4  55-2 

54-47 

55-27 

5-24 

15.13 

15.02 

P 

39-'  39-3  39-7 

39-37 

39-54 

3-73 

13.62 

13.51 

1 

41.1  40  .  9  40  .  2 

40-73 

40.82 

3-87 

13-76 

i3-65 

-.3 

t) 

1Q     i     7Q    2    4.O    8 

^Q    7O 

1) 

SS    7    S6    2    S6    ^ 

c6   O7 

27Q251247 

24.    6^ 

k 

•2-3  .  -J     -12     5    ^2  .  Q 

12    OO 

3  24 

5u 

„  25.5  27-3  28-9 

27.23 

i 

MAGNITUDE. 
IS  14  13  IZ  II  10 


SO 


85/8  Z  CASSIOPCIAE.. 


30 


u 

I- 
u> 


20 


m 


FIG.  34. — MAGNITUDE-CURVE  FOR  Z  CASSIOPEIA. 


CHAPTER  XII. — Z   CASSIOPEIA. 


167 


TABLE    103. — 8518  2,   CASSIOPEIA.     CONSTANTS   FOR   REDUCTION  AND  COMPARISON  WITH 

CATALOGUE  MAGNITUDES. 


6-INCH. 

Star. 

1904  September  5. 

1904  October  i. 

C. 

Obs.  Mag. 

A  Mag. 

C. 

Obs.  Mag. 

A  Mag. 

H. 

P. 

H. 

P. 

H. 

P. 

H. 

P. 

A              ... 

-0.51 

—  0.  12 

6.80 
7-i9 

6.69 
7.08 

+  .32 
-•32 

-f.n 

—  .  12 

—  0.50 

O.OI 

6.75 
7.26 

6.64 
7-'5 

+  .27 
-•25 

+  .06 
-•05 

D  

Means      .    .    . 

7.00 
7-3' 

6.89 
7.20 

±•32 

±.12 

—  0.25 

7.00 
7-25 

6.89 

7-i4 

±  .26 

±.06 

Star. 

1904  October  5. 

1904  October  27. 

C. 

Obs.  Mag. 

A  Mag. 

C. 

Obs.  Mag. 

A  Mag. 

H. 

P. 

H. 

P. 

H. 

P. 

H. 

P. 

A 

-0.63 
-0.23 

6.80 

7.  20 

6.69 
7.09 

+  .32 
-   3i 

+  .11 
—  .  II 

-0.57 
0.07 

6.68 
7-32 

6-57 
7.21 

+  .20 
-  .19 

—  .01 

+  .01 

D              

Means  

-0.43 

7.00 

7-43 

6. 
7- 

89 
32 

±.32 

±." 

-0.25 

7.00 
7-25 

6.89 
7-14 

±.20 

±.OI 

Mn 

12-INCH. 

40-INCH. 

*"•           (ffll 

C. 

Star. 

Mag. 
1  2-inch. 

C. 

h 
Sept.  n.   Nov.  2. 

Nov.  3. 

July  12. 

Oct.  24 

•  Jan.  3. 

Jan.  7. 

a                        82 

9        o.oi          0.63 
5         i  .  50          2  .  06 
5        2.64          3.18 
i        2  .  38          2  .  93 

0.23 
1.72 
2.90 
2.85 

d 
e 
h 
k 
£• 

10.94 
12.25 

10.75 
12.99 
11.97 

0.56 

2.  2O 
0.23 
2.70 

3'57 

2-33 

2.42 

j  y  '  3 
a  ii  c 

4.40 
3.62 

2-77 
2.04 

2-93 

2.  19 

Mean  C    -  .                      i   63 

2.  2O 

9-95 
7-75 

i-93 

9-95 

8.02 

M 

M 
M 

ean  C 

1.42 

"•73 
10.31 

3.86 
12.40 
8.54 

2.38 
12.40 

IO.O2 

2.51 
12.40 
9.89 

Mean  Mag.       9-95        9-9* 
Mo  ....                             8  -*2 

eanMag. 

i68 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABLE  104. — 8518  Z  CASSIOPEIA.     MEAN  MAGNITUDES  OP  COMPARISON  STARS. 


6-INCH. 

Star. 

September  5. 

October  i. 

October  5. 

October  27. 

Mean. 

Mag. 

A  Mag. 

Mag. 

A  Mag. 

Mag. 

4  Mag. 

Mag. 

J  Mag. 

Mag.  H. 

Mag.  P. 

J  Mag. 

A  .. 
D  .. 

Mean 

a.  .  . 
b..  .  . 
d... 
h... 

Mean 
E... 

6.80 
7-19 

+  0.04 
-0.05 

6.75 
7.26 

—  O.OI 
+  0.02 

6.80 
7.20 

+  0.04 
—  0.04 

6.68 
7-32 

-0.08 
+  0.08 

6.76 
7-24 

6.65 
7-13 

±0.04 
±0.05 

7.00  • 

6.89 

±0.04 

8.48 
9.46 

11-13 
10.96 

+  0.19 
—  0.09 
+  0.08 
+  0.05 

8-34 
9-74 
10.96 
10.95 

+  0.05 
+  0.19 
—  0.09 
+  0.04 

8.15 
9-50 

II  .  IO 

10.85 

—  o.  14 
—  0.05 
+  0.05 
—  0.06 

8.18 
9-50 
it  .02 

10.88 

—  0.  II 

—  0.05 
—  0.03 
—  0.03 

8.29 

9-55 
11.05 
10.91 

8.18 

9-44 
10.94 
10.  80 

±0.12 

±0.09 
±0.06 

±0.04 

9  95 
8.04 

9.84 
7-93 

±0.08 
±0.08 

8.15 

+  O.II 

8.07 

+  0.03 

8.06 

+  O.O2 

7.90 

—  o.  14 

12-INCH. 

Star. 

September  n. 

November  2. 

November  3. 

Mag. 

d  Mag. 

Mean. 

Mag. 

A  Mag. 

Mag. 

J  Mag. 

Mag. 

A  Mag. 

Mag.  H. 

Mag.  P. 

A  Mag. 

a.  .  . 
b...  . 
d.  .. 
h... 

Mean 

e  ..  . 
g.... 
k.  .. 

Mean 

8.33 
9.82 
10.96 
10.70 

+  O.OI 

+  0.03 

+  0.02 
—  0.05 

8.38 
9.81 
10.93 
10.68 

+  0.06 

+  O.O2 
—  O.OI 

—0.07 

8.25 

9-74 
10.92 
10.87 

—  0.07 
—  0.05 

—  O.02 
+  O.  12 

8.32 
9-79 
10.94 

10.75 

8.21 

9.68 
10.83 
10.64 

±0.05 
±0.03 
±0.02 
±0.08 

9-95 

9.84 

±0.04 

12.18 

ii-93 
12.94 

—  O.O7 
—  O.O4 
—  0.05 

12.26 
11.97 
13.18 

+  O.OI 

o.oo 

+0.19 

12.32 

I  2.  O2 

12.86 

+  0.07 
+  0.05 
-0.13 

12.25 
11.97 
12.99 

12.  14 

11.86 
12.88 

±0.05 
±0.03 

±0.12 

12.40 

12.29 

±0.07 

40-INCH. 

Star. 

January  3. 

January  7. 

July  12. 

October  24. 

Mean. 

Mag. 

J  Mag. 

Mag. 

J  Mag. 

Mag. 

A  Mag. 

Mag. 

J  Mag. 

Mag.  H. 

Mag.  P. 

J  Mag. 

d 

10.87 
12.51 
10.54 
13.01 

—  O.  12 
+  0.19 

II  .  IO 

12.  II 

+  O.  12 
—  O.2I 

10.98 
12.32 

(io.54 
12.89 

12.  IO 

10.87 

12.21 

10.43) 
12.78 

ii   99 

±0.12     . 

±O.  II 

±0.08 
±0.04 

e  ... 

h  .  . 

12-35 

+  0.03 

12.31 

—  O.OI 

k.  .. 
g.... 

Mean 

n  .  . 

P  •• 
q...  . 
x   . 

12.79 
12.06 

—  o.  10 
—  0.04 

12.82 
12.08 

—  0.07 

—  O.O2 

+  0.  12 

12-94 

12.  16 

+  0.05 
+  0.06 

±0.06 

13-91 
13-58 
I3-76 

—  0.05 
—  0.06 
+  0.04 

'3-94 
13.62 
I3-76 

—  O.O2 
—  O.O2 
+  O.O4 

14.04 
13-72 
13-67 

+  0.08 
+  0.08 
—  0.05 

13.96 
13.64 
13-72 
(13.38 
(13.96 

13-85 
13-53 
13.61 

13-27) 
13-85) 

±0.05 
±0.05 
±0.04 

13.69 
13-38 
I3-96 

—  0.03 

0  ... 

Mean 

±0.05 

CHAPTER   XII. — Z   CASSIOPEIA. 


I69 


TABLE  105. — 8518  Z  CASSIOPEIA.    VISUAL  OBSERVATIONS  OP  THE  VARIABLE. 


No. 

Date. 

Ocular. 

Aperture. 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing. 

/. 

JMag. 

Month 
and  Day 

[our 
.S.T. 

Julian 
Day 
G.  M.  T. 

Steps. 

Mag. 

i 

2 

3 

4 
5 
6 

7 
8 

9 

10 

ii 

12 

13 
14 
15 
16 

17 

18 

19 
20 

21 
22 
23 
24 
25 
26 

27 
28 
29 
3° 
31 
32 

33 
34 
35 
36 
37 
38 
39 

40 
4' 
42 
43 
44 
45 
46 

47 
48 

49 
5° 

51 

52 

53 
54 
55 

1898 
Nov.  ii 
1899 
Jan.     4 

9 

14 
"9 

24 
Feb.     7 
18 
24 
28 

Mar.     7 

13 

28 
Apr.     4 
16 

21 

May   10 

21 

29 
June     7 

10 

July    5 

29 
Aug.  10 
26 
Sept.  13 
25 
Oct.      2 
7 

21 
24 

Nov.    4 

20 
22 
26 

Dec.     4 
19 

23 

1900 
Jan.      i 
8 
20 
Feb.     4 
10 

22 
25 
26 

Mar.     6 

ii 

'9 
3" 

Apr.  29 

May  20 
June  15 
July   12 

7 

7 
7 
6 

7 
7 

'{ 

7 
8 
8 
16 
16 
16 
16 
15 

10 

10 
14 
ii 

10 

9 
9 
8 

7 
8 

7 
8 
8 

2410000+ 
4605.6 

4659 
4664.52! 

4669.54 
4674-54 
4679.50 
4693  52 
4704.54 
4710-54 
47I4.54 
47I4.55 
4721-54 
4727-56 
4742  •  56 
4749.92 
4761.92 
4766.92 
4785-92 
4796.88 
4804.67 
4813.67 
4816.83 
4841.71 
4865.67 
4877.63 
4893.61 
4911.58 
4923.54 
4930.58 

4935  54 
4949^6 
4952  •  56 

80 
150 
200 
40 
150 
150 
200 

15° 
150 
150 
80 

150 

150 

200 
200 

ISO 
150 
ISO 
ISO 
150 
J5° 
15° 
150 

200 

150 
200 
200 

2 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

photograph,  dyv,  vir  

33-4,    32-5  

33-0 

34-4 
32.9 

32-4 
31-9 
3»-4 

29.4 
29.8 

<32 

24.0 

24-3 
23-3 

21.  I 
23± 
<23 
<2I 
<23 
<23 
<23 

<23 
<22 
<22 
<22 
<22 
<22 
<22 
<22 
<2I 
<22 
<22 
<22 

ii.  3± 

II.  IO 

1  1  .29 

11.32 
ii  .40 

"•45 
11.68 
ii  .69 
<n.4 

12.31 

12.27 
12.38 
12.64 

12.  4± 
<I2.4 
<I2.6 

<I2.4 
<I2.4 
<I2.4 
<I2.4 
<I2.5 
<I2.5 
<I2.5 
<I2.5 
<I2.5 
<I2-5 
<I2.5 
<I2.6 
<I2.5 
<I2.5 
<I2-5 

fair 

fair 
fair 
good 
good 

o 

54 
59 

64 
69 

74 
88 

99 

+  o.6± 
+  0.08 

+  0.21 

+0.17 
+  o.  19 
+0.15 
+  o.  19 

+  O.O2 

i>3-4»»',  m'6e   \ 

m'  is  double,  n  and  12*  ) 

-IT   A        28   I      .             .... 

em,  diov  
vie,  g4i>,  diov±  
giv,  ve,  limit  v  

K4T,  ve  
62-3?,  vk  

22.1,     26.4  \ 
24.1,23.5,26.4.:      / 
25-5,     23.1  
23-5.     23.1  
2O.6,     21.6  

fair 

fair 
good 
fair 
poor 

109 
116 

122 

137 
144 

+  0.50 

+0.30 
+0.31 
+0.37 

0.0± 

7 
7 

7 
7 
7 
6 

7 

7 
.     7 
9 
7 
7 
9 
7 
7 
8 
8 

7 
8 

15 

14 
9 
13 

4963-54 
4979-52 
4981.54 

4985  •  54 
4993  •  54 
5008.50 
5012.54 

5021.52 
5028.54 
5040.62 
5055-54 
5061.54 
5073-63 
5076  .  54 
5077.54 
5085  •  58 
5092.58 

5098.54  ' 
5110-56  • 

5139-88- 

5160.83 
5186.63 
52I3-79 

200 

15° 
2OO 
2OO 
ISO 
ISO 
2OO 

ISO 
350 
350 
350 
350 
350 

80 

15° 
150 
150 
150 
40 
40 

150 
40 
150 
150 
150 
237 

6 
6 
6 
6 
6 
6 
6 

6 
40 
40 
40 
40 
40 

12 

6 
6 
6 
6 
6 
6 
6 
6 
6 
( 
6 
40 

<22 

<23 
<2I 
<2I 
<22 
<22 
<22 

<2I 
10.5 
IO.O 

13-7 
18.0 

24.3 
27.2 

25-5 
34-0 
39-5 
40.4 

42.1 

40.0 

38  9 
34-7 
29.1 

<I2-5 
<I2.4 
<I2.5 
<I2.5 
<I2.4 
<I2.4 
<I2-4 

<I2.5 

13.83 
13.90 
13-48 
13.0 

12.27 

11.97 

12.  I 

11.15 
10.50 

10.39 

10.19 

10.44 

10.60 
11.08 
11.72 

moon 
fair 
fair 
good 
good 
good 
poor 
good 
fair 

good 
fair 

good 

good 
poor 
good 

423 

435 
450 
456 
468 

47' 
472 
480 
487 

i 
13 

42 

63 
89 
116 

+0.03 
—  0.41 

+0.58 

+  o.3± 
+0.27 

+  0.18 
+  o.4± 
+  0.03 
-0.37 
—  0.28 

-0.42 

-0.45 

-0.53 
—  0.42 
—  0.24 

V2n,  np,  piq,  qbs,  s8i,  tu. 
XI-2V,  T4-5«,  T>3p,  piq,  qi 
1/3-41,  k4.v,  Ti8n  
lift-  Sx,  v$k,  vie,  dicni  
dSv,  ryv,  -vig,  limit  i<x. 
g2v±,  limit  v  
dm,  -zrjr  
T3-4<*,  V4h  
63-47;,  i'5<f  
63?,  v6d  
61—21;,  v&d  
62—31%  v6—  8<f  
641;,  i/4&  
6411,  T3-4/«,  v$d  
66i)  ±  ,  iijd,  v^h  
h2V,  div,  Vi,r  
a,Ti,  v6e  

15.6,  12.5,  13.0  — 

20.6,  17.6,  16.0.  .  .  . 
24.1,  24.6,  24.1,  24. 
26.6,  27.5,  28.5  — 
25.5  

33-6,    34-5  
38-1,    4'.o  
40.6,    39.6  1 
41.1,    40.6  i 
42.6,    42.6  \ 
41.6,    41.6  j 
40.1,    41.0  J. 
40.1,  40.5,  38.6.  .  .  > 
38.1,  37.6,  41.0.  .  .  . 
35-o,  33-6,  35-5  
29.1,    29.1  

170  RESEARCHES   IN   STELLAR  PHOTOMETRY. 

TABLE  105. — 8518  Z  CASSIOPEIA-     VISUAL  OBSERVATIONS  OF  THE  VARIABLE. — Continued. 


No. 

Date. 

»J 

Aperture. 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing. 

t. 

J  Mag. 

Month 
and  Day. 

Hour 
C.  S.  T. 

Julian 
Day 
G.  M.  T. 

Steps. 

Mag. 

56 
57 
58 
59 
60 
61 

62 
63 

64 
65 

66 

67 
68 
69 

70 

7i 
72 

73 
74 

75 

76 
77 
78 
79 
80 
Si 

82 

83 
84 
85 
86 

8? 
88 

89 
90 

9i 
92 

93 
94 
95 
96 

97 
98 

99 

IOO 
IOI 

1  02 

103 

1900 
Aug.     6 

14 
28 
Sept.    6 
13 
Oct.      4 

16 

24 
1901 
Feb.     9 
Dec.    21 
1902 
Jan.    13 
Oct.      i 

3i 
Nov.     7 
1903 
Oct.    10 
1904 
Aug.     4 
29 

Sept.    5 
ii 
Oct.      i 

8 

27 
30 
Nov.     2 
6 
'4 
'90.S 
Jan.     3 
3 
24 
28 

Feb.     9 

25 
Apr.     4 
ii 
30 
May   22 
June     4 
13 
27 
July   23 

3° 

Aug.     6 

19 

22 
28 

Sept.  17 

Oct.     20 

Nov.  21 

9 
8 
8 
ii 

12 

8 

9 

12 

9 

8 

9 
10 

15 

9 

8 

8 
10 
1  1 

8 
8 
7 
7 
8 

7 
16 
16 
15 
'4 
H 
14 
'4 
1  1 

12 

9 
9 
II 

9 
8 
8 
6 

2410000+ 
5238.63 
5246.58 
5260.58 
5269.71 
5276.75 
5297-58 

5309  63 
53I7-75 

5425-63 
5740.58 

5763  6 
6024.63 
6054.67 
6061.88 

6398 

6697.63 
6722.56 

6729 
6735-58 
6755  67 

6762.71 
6781 
6784 
6787 
6791 
6799 

6849.56 
6849  .  56 
6870.54 

6874.54 

6886  .  56 

6902  .  52 
6940.92 
6947.92 
6966.88 
6988.83 
7001.83 
7010.83 
7024.84 
7050.71 

7057-75 
7064.63 
7077-63 
7080  .  7  i 
7086  .  63 
7106.58 
7139-56 
7«7'-5o 

150 
150 
200 
237 
237 
237 

460 
237 

150 
350 

237 
237 
237 

67 

150 
150 

40 

67 
40 

237 

237 

237 
237 
237 
237 

275 

237 
237 
237 
237 
450 
450 
237 
237 
237 
237 
237 
237 
237 
150 
150 
80 
150 

6 
6 
6 
40 
40 
40 

40 
40 

6 
40 

24 
40 
40 
40 

12 

6 
6 

6 

12 

6 

40 

6 
24 

12 
40 

24 

40 
40 
40 
40 

12 

40 
40 
40 
40 
40 
40 
40 
40 
40 
40 
40 
40 
40 

6 
6 

12 

6 

g3~  41),  i>  limit  

24.0  

24.0 

23-7 
19.8 

21.  I 
21.6 

14-5 
12.8 

12.30 

12.33 
12.80 
12.65 
12.59 
13-38 

13-59 
13-64 

<I2.4 

12.46 
13-15 

12.  2O 
II  .62 

ii   49 

<I2.8 

12.22 
12.40 

<I2.4 

12.95 
<I2.4 

I3.38 
<I2.6 

13.6 

<I2.9 

14.05 
14.1 

14.78 
15.33 

<i4-3 
<i4-3 

<I4  3 

<H-3 
<i4-3 
<H  3 
14.64 

I3-70 
13  63 
13  43 
13  35 
13-5° 
13-38 
13-35 
ii-95 
11.78 

II.  OO 

10.31 
10.51 

II  .  12 

fair 
good 
good 
fair 
moon 
fair 

good 
poor 

fair 
moon 

poor 
fair 
fair 

fair 
good 

good 
good 
good 

good 
fine 

fair 
fair 

fair  \ 
good/ 
fair 
good 

fair 

good 
good 
fair 
fair 
fair 
fair 
good 
good 
fair 
good 
good 
good 
good 
fair 
fair 
good 
good 

141 
149 
163 

172 

179 

200 

212 
2  2O 

151 
174 

435 
465 
472 

124 
149 

162 
189 

21  I 

218 

226 

276 

393 

4'5 
428 

437 
45i 

477 
484 
491 

12 

15 
21 
41 

74 
1  06 

—  0.07 
—  o.  16 
+  0.05 
-0.25 
-0.42 
—  0.07 

—  0.  12 
-0.25 

—  O.06 
+  O.2I 

-i.25± 
—  0.48 

—  O.2I 

+  0.13 
—  O.  IO 

+  0.23 
+  0.18 

+  O.2O 
+  0.09 

—  O.O6 

O.OO 
—  0.40 
—  O.O2 
O.OO 
+  0.55 
+  2.  10 
+  2.42 
+  2.65 

+  1-34 
+  1.15 
+  0.32 

-0.55 
-0.77 
—  0.65 

g3D,  ve,  T>2k  
£41),  km,  limit  v  

CIV     "V\X    . 

24.5   23.1,  23.6  
19.1     20.6  

22.  I       2O.  I  

22   I       211     

xyu,  i>4<7  
£87),  1>4W,  i)3/>,  T>3q,  x$-6v.  . 
photometer  

I4.I        15.0  
(13.6,    12.0,    13.0.  .) 

(140     1  1  6              y 

v  not  seen  limit  e  

<23 

22.7 
16.5 

25.0 
30.0 

ve,  V2k,  1)4-5  x  
ksv,  xyi,  v  5-6  o  

g2D,    1/1-20  

D3g,  v6e±  
photometer  

23.1,  23.6,  21.6  

16.6,  14.1,  18.7  
25-5,  24.6  
30.5,29-1  

i)  not  seen,  limit  2  <  k  

<20 

24.8 
23.1 

<23 

g3D,    TI20  

g4ii,  eiv,  Ti2k  
(photometer,    v   not    seen, 

24-5,25-1  

23.5,  22.1,  23.6  

photometer  

(photometer,    v   not    seen, 

<23 

14.4 

<2I 

#6—81)  k8v  v&p  7)6o 

10.1,  13.6,  18.0,  16.0 

photographs  

v  not  seen,  limit  2  <C  k  

•09 

8.5 

8 

2.0 

no-i7),  1*3-4.1  
photographs  DM 

7-5,  9-5  

m&Ti,  p6v,  u  not  seen  
photometer  

o.o,  4.0  

<   6 
<   6 

<  6 

<   6 
<   6 
<   6 
4.0 
ii.  5 

12.  2 
14.0 

Jn  glimpsed   ?  X3»±,  limit 
(      4—5  <  k  

I 

)  • 

xSn  ±    n2o    w6j  

q2n    pin    no,  n^s  

n$v,  sv,  -viu  

3.0,  6.0,  2.5  

II.O,   I2.O,   I2.O,    IO.9 

13-5,  10.5,  13-9,  ii.  i 

15.0,  13.0,  14.1  — 

112-317,  i>2-3«,  1/40,  x(>v.  .  .  . 
1/4?,  7)5«,  xsv  
photometer  

1)40,  7)39,  xdv  
xyu,  v^q  
3:3-47;,  us?,  1)50  
D7-8:r,  114—51;,  7)g,  hS-iov.  . 
•VIO-I2X,  v^e,  D2g,  h&Ti.  .  .  . 
hi-v,  d2-v,  7)8g±  
667),  1)6/1,  v6d  
v$d,  v6h,  b6v  
dm,  hiv  

13.9,  14.0,  II.  I.  .  .  . 
14-',  15.0  

13.6,  16.0,  14.9.  .  .  . 
24.6,  27.6,  27.5,  28.0 
28±,  28.1,29.5,  29± 
36.0,  34.4,  35  
38.1,  42.0,  42.4.  .  .  . 
38.1,  43.0,  38.1.  .  . 
32.1,    36.0  

'3-4 
14-5 
14.8 

27-3 
28.8 

35-2 
40.8 
39-3 
34-o 

CHAPTER   XII. — Z   CASSIOPEIA. 


CO 
Oi 

00 
N 

2 

CO 

Co 

I 


tk 

CO 
C5 
<i 


3 


S 
§ 


UJ 

o 
o 


01 

o 

0 


0> 

I 


(X 

I 


§ 


FIG.  35. — LIGHT-CURVE  OK  Z  CASSIOPEIA 


172 


RESEARCHES  IN  STELLAR  PHOLOMETRY. 


TABLE  106. — 8518  Z  CASSIOPEI.B.     MEAN  MAGNITUDES  FROM  41  DAY  GROUPS. 


Group    No.  .  . 
I.    D  .  . 

i 
41 

2 
82 

3 
123 

4 
164 

5 
205 

6 

246 

7 
287 

8 
328 

9 
369 

IO 

410 

II 
451 

12 

492 

(I 

o 

64 

IO7 

1  4.0 

4^6 

472 

M 

ii  3± 

T  I      71 

I  2    O7 

I  2    52 

13.  74 

II  .83 

m 

-f  o  6± 

+  o  16 

_f_O    26 

+  O    2± 

4-O    "S4 

-f  o  14 

No 

c 

I 

2 

•2 

6 

!t 

7 

C2 

IO2 

I^I 

184 

216 

M 

12    48 

12    87 

1-262 

JM 

_  O     77 

—  o  06 

—  o  25 

—  o  18 

No 

2 

2 

•I 

1 

2 

r      t 

TCI 

A'l  e: 

468 

M 

It    IS 

12    2O 

ii    ^6 

5589       JM 

—  o  06 

-f-O    21 

—  I     25 

—  O    74. 

I  No. 

I 

I 

I 

2 

f       / 

145 

189 

218 

276 

393 

433 

M 

12     52 

I-i-iS 

T  T     OS 

i  s  06 

T  7    E;-I 

6™\    m 

+  o  09 

•fo   18 

+  O    IO 

+  o  06 

o  oo 

+  o  04 

I  No. 

3 

i 

3 

i 

i 

4 

r    t 

Means  \      * 
L  No. 

5 
10.63 
—  0.03 

3 

61 
11.08 

—  O.O2 

7 

106 

11.88 
+  0.09 

7 

147 
12.50 
-f  0.05 

9 

185 

13  °3 
—  0.05 

5 

217 
13.82 

—  O.OI 

5 

276 
15.06 
+  0.06 
i 

.... 

393 

14.64 
o.oo 

I 

436 
13-44 

—  O.OI 
8 

471 

II  .76 

—  O.02 

8 

IOO 


ZOO 


3OO 


DAYS 


44O 


50O 


600 


to  m  

1  "  s  ~                 " 

i  *  ^ 

X          

_  __  _j  _  j  _  ^ 

H    .  . 

--  85/8    Z   CAS$!QP£IA£        /  

"  " 

If       \ 

^  ^ 

r 

"I 

^ 

wax.  «.^>t^"                               -H-  - 

c 

.       »                       -»  -~*r\  SJ 

^ 

Af//7.  =  329°                                \l\ 

r 

M-  m  „  /?£</              ":;:*JL::::I 

^ 

• 

/? 

v                                                                                                       F* 

^ 

..&.. 

-4 

Q        I        .     . 

^  

j  

r 

* 

^ 

.           -  _ 

£/  3  

VB  .  

.j  —  .  — 

3 

Z 

t 

T 

I)      .    

::::i::iS:       i    :::::: 

j  

2     i:::::::::::::;::::;: 

-  -  r  -• 

^_- 

] 

-  Si  - 

;::  —  t 

f 

V 

7 

s     

^  

::  5  — 

c 

t~  "iiniii:  i.i 

HI  1 

__z  it  

*  ^ 

16  : 

FIG.  36. — MBAN  LIGHT-CURVB  OF  Z  CASSIOPBI.U. 


CHAPTER   XII. — Z   CASSIOPEIA. 


173 


TABLE  107.— 8518  Z  CASSIOPEIA.    OBSERVED  MAXIMA  AND  MINIMA. 

Elements  of  maximum.     1898  Nov.  22  (J.  D.  2414617)  +  492"1E.     M-m=173«. 


MAXIMA. 

MINIMA. 

ja 

o 

a 

M 

Date. 

Mag. 

Corr. 

Wt. 

i 

w 

Date. 

Mag. 

Corr. 

Wt. 

Calendar. 

J.  D. 

H. 

P. 

Calendar. 

J.  D. 

H. 

P. 

o 
i 

2 

4 

1903  Nov.  2  7 
1900  Apr.   3 
1901  Aug.  1  8 
1  904  Apr.  1  1 

4622 
5"3 
5615 
6582 

10.7 

IO.2O 

me 
me 

10.6 
10.09 

+  5 
+  4 
+  14 
-  3 

9 
35 

i 

4 

I 

2 

3 
5 

1  899  Oct.    9 
1901  Feb.  24 
1902  June   2 
1905  Feb.  ii 

4937 
5440 
5903 
6888 

me 
me 
me 
15-18 

+  i 

—  12 

-17 
-16 

2 
2 

6 
15 

'5-07 

The  mean  light-curve  was  formed  from  the  observations  up  to  1905  June 
27,  and  gives  the  mean  period  492  days.  The  last  minimum,  1905  February  16, 
is  the  only  one  well  covered  by  the  observations.  The  five  comparisons  between 
1905  January  24  and  April  n  were  made  with  difficulty,  owing  to  the  low  posi- 
tion of  the  field  and  the  faintness  of  the  variable,  which  seems  to  have  been  fainter 
than  the  star  n.  On  account  of  the  difficulties  mentioned,  the  stars  n  and  s  were 
taken  for  the  variable  and  n,  but  the  real  brightness  of  the  variable  is  shown  by 
the  observations  of  January  3  and  April  30.  The  comparisons  made  in  May,  June, 
and  July  show  an  unmistakable  halt  in  the  rise  between  the  i3th  and  i4th  magni- 
tude, followed  by  a  sudden  increase  of  more  than  one  magnitude  between  August 
6  and  19.  The  corresponding  rise  in  February,  1900,  was  less  rapid. 

The  period  492  days  satisfies  the  present  series  of  observations,  and  there 
seem  to  be  no  others  for  comparison  until  Hartwig's  are  published. 


CHAPTER  XIII. 

8629  Y  CASSIOPEIA. 

* 

R.  A.  23»<58n>  135.8;  Dec.  +55°  7'  35*  (1900). 

This  variable  was  discovered  by  Mrs.  Fleming  in  1898  at  Harvard,  from  the 
bright  hydrogen  lines  in  its  third  type  spectrum.  H.  C.  O.  Circular,  No.  24, 
states  that  there  are  101  plates  containing  the  field,  so  when  these  are  measured 
the  variation  of  the  star  will  be  thoroughly  known.  The  brighter  stars  in  the 
field  were  measured  with  the  6-inch  in  February  and  March,  1898,  and  the  place 
of  the  variable  relative  to  the  stars  A  and  B  (Cambridge  A.  G.  catalogue)  found 
as  given  above.  The  stars  b,  e,  and  /  were  connected  with  the  variable  with  the 
micrometer  on  the  4O-inch  in  February,  1900.  The  star  e  was  found  to  be  double, 
about  i3th  and  i4th  magnitude,  position  angle  198°,  distance  6".6. 

Visual  comparisons  of  the  variable  began  in  February,  1898,  a  little  too  late 
to  definitely  fix  the  maximum,  which  the  mean  light-curve  aids  in  placing  at 
March  n,  9.4  magnitude  on  the  Harvard  scale.  The  decline  following  this  maxi- 
mum was  followed  with  the  6-  and  1 2-inch  telescopes,  and  at  the  minimum  the 
star  remained  below  the  limit  of  the  6-inch  for  91  days,  from  1898  September  7 
to  December  7.  The  next  maximum,  1899  April  8,  was  well  covered  with  the 
6-inch,  and  the  variable  was  found  at  minimum  with  the  4o-inch,  1900  January 
8  (minimum  by  mean  curve,  1899  December  13).  The  adopted  magnitude  at 
the  next  maximum  would  be  9.6  or  10.6,  according  to  the  weights  given  to  the 
discordant  observations  of  June  15  and  July  12.  The  probable  course  of  the 
variations  from  October,  1900,  to  August,  1904,  is  shown  by  the  broken  line  in 
fig.  38,  fixed  by  the  aid  of  the  mean  light -curve,  guided  by  occasional  observa- 
tions sufficient  to  give  the  number  of  the  epoch.  From  August,  1904,  regular 
comparisons  fix  the  maximum  of  epoch  6  and  the  following  minimum,  and  show 
that  the  adopted  period,  410  days,  is  substantially  correct. 

TABLE  108. — 8629  Y  CASSIOPEIA.     STANDARD  MAGNITUDB  STARS. 


Star. 

B.  D.  No. 

1900. 

Color 
P.  DM. 

Magnitude. 

Residuals. 

R.  A. 

Dec. 

Catalogue. 

Measured. 

I''f  m  Cats. 

3 
Nights 
inter 
se. 

H.C.O. 

P.  DM. 

H. 

P. 

H. 

P. 

C 
F' 
G 

0 

+  54  3109 
+  55  3°55 
+  55  3041 

h    m     s 
oo  oo  30 

23  5i  53 
23  49  02 

o        / 

+  55  09-2 
+  55   17-° 
+  55  56.0 

G- 
WG 
G 

7  .11 
7.01 
7.48 

7-05 
6.57 
7.16 

7.29 
6.88 
7-43 

7.02 
6.61 
7.16 

+  18 
-»3 
-   5 

-   3 
+   4 
o 

±4 
±6 
±6 

7.20 

6-93 

7.20 

6.93 

±12 

±    2 

±5 

»75 


1 76 


RESEARCHES   IN  STELLAR   PHOTOMETRY. 


MAGNITUDES   OF   COMPARISON   STARS. 

The  standard  magnitude  stars  in  the  two  fields  in  the  constellation  Cassiopeia? 
are  distinguished  from  those  in  the  other  ten  fields  in  that  they  are  fainter  in 
the  Harvard  than  in  the  Potsdam  Catalogue.  The  difference  is  only  — o.  n  in 
the  Z  Cassiopeia?  field,  where  it  might  be  partially  accounted  for  by  the  use  of 
only  two  stars.  But  in  this  field,  for  three  stars,  the  difference  amounts  to 
—0.27.  That  this  is  not  accidental,  nor  entirely  due  to  the  star  colors,  is  shown  by 
the  standards  in  two  "  Rumford"  fields,  U  and  S  Cassiopeiae,  where  the  differences 
are  — 0.16  and  —  o.oi,  respectively,  so  that  the  mean  difference  for  the  four  fields 
in  this  constellation  is  —  0.14,  as  compared  with  +0.29  for  the  other  ten  fields 
here  considered.  If  the  Harvard  scale  is  adopted  for  this  field  the  limit  of  vision 
of  the  6-inch  becomes  13.53  from  the  star  «,  an  abnormally  faint  limit. 

TABLE  109. — 8629  Y  CASSIOPEIA.    COMPARISON  STARS  IN  B.  D.  CATALOGUE. 


B.  D. 

1855- 

B.  D. 

1855- 

btar. 

No. 

Mag. 

R.  A. 

Dec. 

otar. 

No. 

Mag. 

R.  A. 

Dec. 

O 

h  m  s 

O     / 

o 

h  m  s 

0     / 

P 

+  54  3096 

9-5 

23  54  45 

+  54  38.5 

.r 

+  54  3102 

9-5 

23  55  42 

+  54  45-6 

0 

+  54  3098 

9i 

23  54  55 

+  54  36.7 

A 

+  54  3103  ' 

79 

23  56  2 

+  54  44-9 

I 

+  54  3099 

9-5 

23  55  3 

+  54  48.8 

m 

+  54  3'°5 

9-5 

23  56  42 

+  54  54-0 

B 

+  54  3ioi 

8-3 

23  55  '3 

+  54  46.9 

0 

+  55  3078 

9-i 

23  56  4° 

+  55  13-3 

TABLE  no. — COMPARISON  STARS  FOR  Y  CASSIOPEIA  (IN  ORDER  OP  RIGHT  ASCENSION). 


Star. 

Coordinates  from  Variable. 

Light 
Scale, 
Steps. 

Magnitude. 

R.  A. 

Dec. 

Measured. 

From  Curve. 

H. 

P. 

H 

P. 

P' 

0 

1 

o' 
B 
k 
h 
s 
P 

I 
d 

1 

2* 

e 
a 
c 

n 
t 
ft 
m 

r 

n 

-637 
-536 
-509 

-457 
-438 
-397 
-186 
-125 

—  122 
—  122 
-     87 

+        I 

+    19 
+   23 
+  49 
+  5i 
+   54 
+  60 

+  IIO 

+  128 
+  223 

+  393 
+  426 

+  479 

j 

-74-3 
-62.5 

-59-4 
-53-3 
-5i-i 
-46.4 
-21.7 
—  14.6 
-14.2 
-14.2 

—  IO.2 
+    O.I 

+    2.2 
+    2.7 
+    5-7 

+   6.0 
+   6.3 
+   7-0 

+  12.8 

+  14-9 
+  26.0 

+  45-8 
+  49-7 
+  55-9 

ft 

-  822 

-   945 
+   328 
-    170 

+   343 
-   387 

+     112 

+     92 
—   426 

+  406 
+    64 
+   50 

+   141 
+       6 
-   470 
-      73 
+     50 
-    103 
+    in 
+  497 
-   505 
+  1287 
+    150 
+    139 

27.2 

9-'7 

8.90 

23.2 

9.87 

9.60 

4-4 
7-i 

8-35 

IO.  10 

8.08 
9-83 

13.09 
12.60 

12.82 
12.33 

6.0 

19.6 
10.8 
7-8 

0.0 

5-9 

2.1 
I6.3 

12.82 
10.46 

"•43 
12.13 

7-77 
14.01 

13-53 
10.71 

12-55 

10.  19 
n  .  16 
11.86 
7-50 
13-74 

13.26 
10.44 

12.83 

12.56 

31-8 
25.0 

10.02 

9-75 

8.40 

8.13 

*The  preceding  component. 


STELLAR   PHOTOMETRY. 


+  i 


N 

Om 


PLATE  13. 


•n 


.-P 


•d. 

"e.   J> 
f-0 

a    ' 


-.A       ••< 


t 


+20' 


— +10' 


o' 


>P  . 


Scale,  i  mm=  I3".6. 


1902  August  15. 


8629   Y  CASSIOPEIA. 
R.  A.  23h  58m  I39.8.      Dec.  +55°  7'  25".     1900. 


CHAPTER   XIII. — Y   CASSIOPEIA. 


177 


TABLE  in. — 8629  Y  CASSIOPEIA.    PHOTOMETER  MEASURES  OF  COMPARISON  STARS. 


1904  October  6.                                             6-INCH.                                                                       Fine. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings 

C. 

Magnitude. 

Mean  of  3 

Mean  of  6 

H. 

P. 

h    m 
21   38 

31    56 

o 

27 
25 

Cal 
m 

V 

A 
B 
I 

F'a, 
Gai 
Goi 
F'o- 

l 

B 
A 
m 
Ca. 

12.6  12.7  12.  i 
28.8  30.0  30.0 
34-9  36-1  35-3 

IO.2    IO.2    IO.O 

15.1  15.0  15.0 
28.  I  28.0  27.9 

IO.O    IO.O      9.2 

12.9  14-3  13-7 
13.1  13.8  13.3 

8.8     9.6     8.9 
26.  i  25.8  27.2 
14.3  15.0  14.7 
10.9  it.  i   10.8 
29-  7  30.0  29.0 

12.2    II.  7    12.  O 

12.27 
29.60 

35-43 
10.13 
15-03 
28.00 

>3-63 
'3  63 
13  40 
9.  10 
26.37 
14.67 
10.93 
29-57 
11.97 

12.  12 

29-59 

0.52 
2.63 
3  40 
o-35 
0.91 
2.36 
0.23 
0.72 

7.98 
10.09 
10.86 
7.81 

8-37 
9.82 
7.69 
8.18 

7-7i 
9.82 
10.59 

7-54 
8.  10 

9  55 
7-42 
7-91 

'0.53 
14.85 
27.19 
9-42 
13-52 

1904  October  15.                                                                                                                             Good 

o     26 
o     50 

16 
18 

Gai 

G 
F'a, 

I 
B 
s 
A 
m 
C 
C 
m 
•v 
A 
B 
I 

F'a, 
Gai 

16.9  18.4  17.5 

10.3     II  .O    II  .2 

10.8  11.3  10.  2 

31.7  32.1  32.2 

17.1   18.1   18.1 

32-9  33  i  32-7 
13.1   14.0  13.4 

31-7  32-9  32-4 

IO.O    IO.O      9.2 

10.  i     8.9     9.7 

32.0  33.6  33.4 

35-6  36-1  34-7 
15.0  13.9  14.7 
18.3   18.0  18.2 
31.0  30.7  31.1 
13.4  12.6  12.8 
17.  i    16.4  16.9 

17.60 
10.83 
10.77 
32.00 

'7-77 
32.90 
13-50 
32.33 
9-73 
9-57 
33  oo 

35-47 
14-53 
18.  17 

30.93 
12.87 
16.80 

17.20 

1.24 

0-37 
0.49 
2.86 

1-35 
3  04 
0.78 
3  .02 
0.25 

8.28 
7.41 

7-53 
9.90 

8-39 
10.08 
7.82 
10.06 
7.29 

8.01 

7.14 
7.26 
9-63 

8.12 

9.81 
7-55 
9-79 
7.02 

ii  .82 
3'-47 
17-97 

14.02 
32-67 
9-65 

3-40 

10.44 

10.  17 

1904  October  27.                                                                                                                             Fjne 

21       O 
21     18 

3i 
28 

Gai 
F'a, 
/ 

B 
t 
A 

V 

m 
Ca, 
Ca, 

m 
A 
B 
I 
F'o, 
<7a, 

'2-7    13-7    13-6 

9.6     8.6     9.2 
27.5  28.0  27.6 
13-7   13-9  13  6 
27.8  28.0  29.0 
9.1   10.4     9.8 
23.2  24.4  24.0 
28.0  28.2  28.  i 
12.9  12.9  13.8 
13.3  14.0  12.8 
29.0  28.5  29.3 
9.6  10.3  ii  .  i 
15.1   15.8  15.0 
28.5  28.1   28.9 

IO.O    IO.I    IO.I 

13.2  13.0  13.8 

13.33 
9.13 
27.70 

13-73 
28.27 

9-77 
23  -  8? 
28.10 
13.20 

'3-37 
28.93 

10.33 
15-30 
28.50 
10.07 
13-33 

13-33 
9.62 
28.  10 
I4-52 

0.68 
0.25 

2-47 
0.87 

2-47 
0.28 
2.03 

2-51 
0.68 

8.09 
7.66 
9.88 
8.28 
9.88 
7.69 
9-44 
9-92 
8.09 

7.82 
7-39 
9.61 
8.01 
9.61 
7.42 

9-17 
9-65 
7.82 

10.05 

28.52 
13-29 

178  RESEARCHES   IN   STELLAR    PHOTOMETRY. 

TABLB  in. — 8629  Y  CASSIOPEIA.     PHOTOMETER  MEASURES  OP  COMPARISON  STARS. — Continued. 


1904  September  2.                                          12-INCH.                                                                  Good. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

P. 

k   m 
'9  35 

19  53 

o 
44 

40 

I 
B 

Bai 

A  at 
V 
b 

d 
c 
m 
m 
c 
d 
b 
A  oi 

Bai 

B 
I 

20.  o  20.9  21  .0 
5.0     6.7     5.6 
14.2  14.4  14.8 
10.  7   10.  i    10.  i 
36.2  36.8  36.9 
27.9  28.0  28.  i 
35-o  35.1  35-o 
30.0  29.3  30.2 
22.0  23.1  23.1 
23.2  22.9  23.6 
31.0  30.9  29.9 
36.6  36.4  36.2 
26.1  28.7  26.9 
9.0  10.1   10.0 
14.0  15.1   14.9 
6.7     7.2     6.7 
20.7  20.7  20.3 

20.63 
5-77 
H-47 
10.30 
36.63 
28.00 
35.03 
29.83 
22.73 
23-23 
30.60 
36.40 

27-23 
9.70 
14.67 
6.87 
20.57 

20.60 
6.32 

'4-57 

IO.OO 

1.78 

O.22 
I  .OO 

0-44 
3-40 
2-43 
3-27 
2.67 

2.OI 

9.84 
8.28 
9.06 
8.50 
ii  .46 
10.49 
"•33 
10.73 
10.07 

9-57 
8.01 
8.79 
8.23 
11.19 

10.22 
II  .06 
10.46 
9.80 

27.62 

35.72 
30.22 
22.98 

1904  November  2.                                                                             Fair,  a  little  dull  and   unsteady. 

21       1 

21  24 

3i 
28 

I 
B 
s 
Aai 

V 

b 
d 
c 
m 
m 
c 
d 
b 
Aai 
S 
B 
I 

25.6  24.4  25.1 

12.  O    12.  O    II.  8 
27.8    28.8    28.2 
14.9    14.6    15.0 
19.7    19.7     18.9 
32.3    32.1    32.1 
42.7    42.5    42.1 

33  2  33  9  32.9 
27.3  28.0  27.4 
27.9  27.8  27.7 
34.8  34.1  33.4 
40.4  40.9  41  .6 
32-1  33-3  32-8 
12.8  12.4  13.3 
29.  i  29.2  28.7 

12.  I    12.6    12.  I 
26.6    27.  I    26.  I 

25-03 
"•93 

28.27 

14-83 
'9-43 
32-17 
42-43 
33-33 
27-57 
27.80 
34-10 
40.97 

32.73 
12.83 
29.00 
12.27 
26.70 

25.87 

12.  IO 
28.64 
I3.83 

2.27 
0.69 
2.52 
0.90 
1.64 
2.90 

3-97 
3  05 
2-43 

9.87 
8.29 

IO.  12 
8.50 
9.24 
10.50 

"•57 
10.65 
10.03 

9.6o 
8.02 
9.85 
8.23 

8-97 
10.23 
11-30 
10.33 
9.76 

32.45 
41.70 

33-72' 
27.69 

1904  November  3.                                                                                                                          Good. 

21       I 
31    2O 

30 
28 

m 
c 
d 
b 
V 
A  at 
S 

B 
I 
I 
B 
s 
.Am 
b 
d 
c 
m 

24-9    25.3    25.1 
31-9    30.9    3I-I 

36-5  37-6  36.7 
28.0  28.7  27.8 
16.2  16.6  16.4 

IO.I    IO.  I       9.2 

24.5  24.9  24.3 
8.2     7.9     6.9 

23.2    22.8    23.2 
22.7    23.3    22.4 
7.8       7.1       7.3 
23.0    24.1    24.2 

8.2     9.8     9.0 

27.5  27.0  27.7 
38.0  37.4  37.3 
31.2  31.2  32.1 

24.2  24.0  24.0 

25.10 
31-30 

36-93 
28.17 
16.40 
9.80 

24-57 
7.63 
23-07 
22.80 
7.40 
23-77 
9.00 
27.40 
37-57 
31-47 
24.07 

24-59 
31-39 
37-25 
27-79 

2.26 
2.78 

3-44 
2.44 
1.24 
o-37 

2.  12 
O.2I 
2.OI 

IO.22 
10.74 
II  .40 
10.40 
9.2O 

8-33 
IO.O8 

8.17 
9-97 

9-95 
10.47 
11.13 
10.13 

8  93 
8.06 
9.81 
7.90 
9.80 

9.40 

24-15 
7-52 
22.94 

CHAPTER  XIII. — Y   CASSIOPELE.  179 

TABLE  in.— 8629  Y  CASSIOPEIA     PHOTOMETER  MEASURES  OP  COMPARISON  STARS. — Continued. 


1902  December  26.                                            40-INCH.                                                   Clear,  unsteady. 

Sidereal 
Time. 

Zen. 
Dist. 

Star. 

Scale  Readings. 

Mean  Scale  Readings. 

C. 

Magnitude. 

Mean  of  3. 

Mean  of  6. 

H. 

p. 

h    m 

4  25 

O 

c 
d 
b 

V 

} 
a 
a 

b 
d 
c 

16.9  18.5  17.9 
25.0  24.3  25.0 
12.8  12.9  13.4 
30.7  30.1  31.0 
30.8  32.1  31.9 
44.8  43.8  43.7 
44-7  44-4  44-2 
29-8  30.7  30.9 
14.3  12.6  13.8 
25.8  26.4  26.3 
19.2  18.5  19.3 

17-77 
24-77 
13-03 
30.60 
31.60 
44.10 
44-43 
30-47 
13-57 
26.  17 
19.00 

18-39 
25-47 
13-30 

1.49 

2.24 
0.82 
2.71 
2.76 
4-25 

10.84 

"•59 
10.  17 
12.06 

12.  II 
13.60 

10.57 
11.32 
9.90 
11.79 
11.85 
13.33 

31.04 
44-27 

1905  January  7.                                                                                                             Clear,  unsteady. 

4    6 

42 

c 
d 
b 

f 
a 
a 
Vai 

b 
d 
c 

14.0  14.9  15.3 

21.9    21  .8    22.2 

7.2     8.6     9.1 

26.2    29.3    28.7 

36.3  37-1  37-7 
37-3  37-5  38-1 
16.1   16.0  14.8 
28.3  28.6  29.0 
ii.  o     9.2   10.3 

24.6    22.2    24.5 

13.9  16.3  16.1 

14-73 
21-97 
8.30 
28.07 
37-03 
37.63 
15-63 
28.63 
10.  17 

23-77 
15.10 

14.92 
22.87 
9.24 
28.35 
37-33 

1  .04 
2.06 

0.37 
2.50 

3-47 

10.75 
11-77 
IO.O8 
12  .21 
I3.I8 

10.48 
11.50 
9.81 
11.94 

12.91 

1-15 

10.86 

10.59 

1905  January  28.                                                                                                                            Good. 

4  10 

4  20 

44 

c 

d 
b 

•v 

! 

a 
a 

f 
•u 
b 
d 
c 
g 

13.2   13.8  12.8 

20.3    20.3    21.  I 

4-8     7-9     8.3 
9.2     8.1     8.2 

22.8    25.7    24.9 

38.3  37  2  37.3 

36.4  36.9  36.0 
25.2  24.4  24.1 

7.4     8.2     8.1 
7-3     7-8     8.3 
18.8  20.2   19.5 

12.  I    13.7    12.3 

24.1  23.7  24.0 

13-93 
20.57 
7.00 
8.50 

24-47 
37.60 

36-43 
24-57 
7.90 
7.80 
19-50 
12.70 
23-93 

I3-32 
20.04 
7.40 

8.20 

24-52 
37.02 

0.83 
1.72 

O.2O 

o.  26 

2.17 

3-44 

10.78 
ii  .67 
10.15 

10.21 
12.  12 
13-39 

10.51 
II  .40 

9.88 

9  94 
11.85 
13.12 

2.  2O 

12.15 

11.88 

1900  July  12.                                                  WEDGE  II.                                                     Fair,  moon. 

22    2O 

b 

I 
d 
c 

9 

z 
a 

f 

V 

13-2   15-5  13-0  I 
ii.  8  ii.  8   > 
24.0  25.8  28.0  I 

13.06 
26.20 
25-05 
16.88 

32.93 
43-5 
43-20 

26.53 
15-55 

0.42 

2-44 
2.26 
I  .OO 

3-19 
4-32 
4-30 

10.06 
12.08 
II  .90 
10.64 

12.83 
13-96 
13-94 

9-79 
IX.  8l 

11.63 
10.37 

12.56 
13.69 
13-67 

26.36 

24.7  26.0  25.1   ) 

17.0  16.  i   16.4  \ 
18.0   ) 

34.0  32.4  33.0  ) 
32-3   > 
43  5       •  • 

43-7  45-o  43-7  I 
42  4   ) 

24.0  27.7  29.2  ) 

2s  2  .      .  .  .  .  f 

0.77 

10.41 

10.  14 

15-9  15-2  .... 

iSo 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABLE   112. — 8629  Y  CASSIOPEIA.     CONSTANTS  FOR  REDUCTION  AND  COMPARISON  WITH  CATALOGUE 

MAGNITUDES. 


6-INCH. 


1904  October  6. 


1904  October  15. 


1904  October  27. 


Star. 


C. 


Obs.  Mag. 


H.      P. 


A  Mag. 


H. 


C. 


Obs.  Mag. 


H. 


P. 


A  Mag. 


H. 


P. 


C. 


Obs.  Mag. |      A  Mag. 


H. 


P. 


H. 


P. 


C.... 
F' .... 
G.... 


-0.23 
-0.52 
-0.03 


7-23 
6  94 

7-43 


6.96  +  .12 
6.67!  —  .07 
7.l6; -.05 


-.09 

+  .10 

.OO 


0.25 

-O.26 

0.49 


7.29 
6.78 

7-53 


7.02 

6.51 
7.26 


+  .18 
-•23 
+  .05 


-  03 
-.06 
+  .10 


-0.07 
-0.50 
-0.07 


7-34 
6.91 

7-34 


7.07  +.23 
6.64  —  .  10 
7.071-  .14 


+  .02 
+  .07 
-.09 


Means 

Mo.., 


—  O.  26 


2O6 


7 
7.46 


•93±-°8 
7.19 


±.06 


o.  16 


7.20 
7.04 


6-93 
6.77 


±.'5 


±  .06 


7-206.93 
7-41  7- '4 


±.16 


±.06 


12-INCH. 


Star. 


Mag. 
6-inch. 


A 
B. 

I  . 


Mean  C  .  . . . 
Mean  Mag.. 
M0.. 


7-77 
8-35 
9.87 

IO.O2 


8.96 


C. 


Sept.  2.     Nov.  2.     Nov.  3 


-0.40 

O.22 

1.78 

2.OI 


0.90 
8.96 
8.06 


0.06 
0.69 

2.27 

2.43 


1.36 

8.96 
7.60 


-0.47 

O.2I 
2.OI 
2.26 


I. 21 
8.96 
7.96 


40-INCH. 


Star. 


Mag. 
i  z-inch 


10.46 
10.71 
"•43 


Mean  C. . 

Mean  Mag  . I    10. 87 

If... 


C. 


Dec.  26.  Jan.  7.  July  12.  Jan.  28 


0.82 
1.49 

2.24 


1-52 

10.87 

9-35 


0-37 
1.04 
2.06 


1.16 

10.87 

9.71 


0.42 
i  .00 
2.26 


1.23 

10.87 

9.64 


O.20 
0.83 
1.72 


0.92 
10.87 

9-95 


MASNITUOE 


tf                             5/4/3                        1 
JO  -- 

::::::::::::  86^9  Y  CASSIOPF/AC 

to  —  i  -  _  : 

>    [-|  1  1 

^                   //                    to                   9                    5 

1  1*^  ~~~ 


10  --                -  -  I  —  ,- 

lliililiiiiliii 

.  —  ^  

~  —  P*  —  

FIG.  37. — MAGNITUDE-CURVE  FOR  Y  CASSIOPEIA. 


CHAPTER  XIII. — Y   CASSIOPELE. 


181 


TABLE  113. — 8629  Y  CASSIOPEIA.     MEAN  MAGNITUDES  OP  COMPARISON  STARS. 


6-INCH. 

Star. 

October 

6. 

October  15. 

October  27. 

Mean. 

Mag. 

A 

Mag. 

Mag. 

A  Mag. 

Mag. 

A  Mag. 

Mag.  H. 

Mag.  P. 

A  Mag. 

c             

7.23 
6.94 

7-43 

—  0.06 
+  0.06 
o.oo 

7.29 
6.78 
7-53 

o.oo 

—  O.  IO 
+  O.  IO 

7-34 
6.91 

7-34 

+  0.05 
+  0.03 
—  0.09 

7.29 

6.88 
7-43 

7.02 
6.61 
7.16 

±0.04 
±0.06 
±0.06 

F'         

G  

Mean      

7.20 

6-93 

±0.05 

A       

7.81 

8-37 
9.82 
10.09 

+0.04 

+  O.O2 
—  0.05 
+  0.07 

7.82 

8-39 
9.90 
jo.  06 
10.08 

+0.05 
+0.04 
+0.03 
+  0.04 

+  O.  IO 

7.69 
8.28 
9.88 
9.92 
9.83 

-0.08 
—  0.07 

+  O.OI 
—  O.IO 
—  O.  IO 

7-77 
8-35 
9.87 

10.  O2 

9.98 

7-50 
8.08 
9.60 

9-75 
9.71 

±0.06 
±0.04 
±0.03 
±0.07 

±0.10 

B  

/                    

s    

9.00 

8-73 

±0.06 

12-INCH. 

Star. 

September  2. 

November  2. 

November  3. 

Mean. 

Mag. 

A 

Mag. 

Mag. 

JMag. 

Mag. 

A  Mag. 

Mag.  H. 

Mag.  P. 

A  Mag. 

A         

7.66 
8.28 
9.84 
10.07 

+  0.06 
+  0.03 
—0.05 
—  0.04 

7.66 
8.29 
9.87 
10.03 

+0.06 
+  0.04 

—  O.O2 
-0.08 

7-49 
8.17 

9-97 

IO.22 

—  O.  II 

+  0.08 
+  0.08 

+  O.II 

7.60 
8.25 
9.89 

10.  11 

7-33 
7-97 
9.62 
9.84 

±0.08 
±0.05 
±0.05 
±0.08 

B  

/  

8.96 

8.69 

±0.06 

b      

10.49 
10.73 
"•33 

+  0.03 

+  O.O2 
—  O.IO 

10.50 
10.65 
11-57 

10.  12 

+  0.04 
—  O.O6 
+  0.14 
+  O.O2 

10.40 
10.74 
II  .40 
10.08 

—  0.06 
+0.03 
—0.03 

—  O.O2 

10.46 
10.71 
>i-43 

IO.  IO 

10.  19 
10.44 
ii  .  16 
9.83 

±0.04 
±0.04 
±0.09 

±0.02 

c    

d      

10.68 

10.41 

±0.05 

40-INCH. 

December  26.          January  7.              July 

Qfnr 

12. 

January  28. 

Mean. 

Mag.       A  Mag.      Mag. 

A  Mag.     Mag. 

d  Mag 

Mag. 

A  Mag 

Mag.  H. 

Mag.  P. 

A  Mag. 

b....     10.17    +0.05      10.08 
c...     10.84    +0.09      10.75 
d...     11.59    —0.14      11.77 

—  0.04      10.06 
o.oo      10.64 
+  0.04      11.90 

—  O.O2 
—  O.II 

+  0.17 

10.15 
10.78 
ii  .67 

+  0.03 
+  0.03 
—  0.06 

IO.  12 
10.75 

ii   73 

9-85 
10.48 
ii  .46 

±0.04 
±0.06 

±O.  IO 

10.87 

10.60 

±0.07 

/.  .  .      12.  II      —  O.O2        12.21 

a...     13.60    +0.07      13.18 

+  0.08      12.0 
-0-35      13-9 

12.8 

S 

I 
I 

—  0.05 
+  0.39 
-0-34 

12.  12 

13-39 
12.15 

—  O.OI 

—  0.14 

-0-34 

12.13 

13.53 

12.  5± 

11.86 
13.26 

12.  2± 

±0.04 
±0.24 

±0.14 

182 


RESEARCHES   IN   STELLAR  PHOTOMETRY. 


TABLE  114.— 8629  Y  CASSIOPEIA.    VISUAL  OBSERVATIONS  OP  THE  VARIABLE. 


No. 

Date. 

Ocular. 

3 
& 

Comparisons. 

Reduction,  Steps. 

Means. 

Seeing. 

t. 

A  Mag. 

Month 
and  Day. 

Hour 
C.S.T. 

Julian 
Day 
G.  M.  T. 

Steps. 

Mag. 

i 

2 

3 

4 

5 
6 

7 
8 

9 

IO 

ii 

12 
13 
14 

15 
16 

17 
18 

19 
20 

21 
22 
23 
24 
25 
26 

27 
28 
29 
30 
31 
32 

33 
34 
35 
36 

37 

38 
39 
40 

41 
42 
43 
44 
45 
46 

47 
48 
49 
50 
51 
52 
53 

1898 
Feb.   15 

23 

24 
Mar.     4 

5 
"3 
16 

23 
28 

Apr.     6 
20 

25 
June  21 

July     6 

Aug.     i 

9 
18 
Sept.    7 
Oct.      5 
Nov.     5 
19 
30 
Dec.     7 

IO 

26 

3° 
1899 
Jan.      6 
H 
27 
Feb.     7 
28 
Mar.     7 

13 
28 
Apr.     4 
16 

May     i 

21 

June     7 
15 
July     5 
ii 

Aug.    6 
26 
Sept.  13 
26 
Oct.     2 
Nov.     6 
20 
27 
Dec.     6 

8 
7 
7 

7 

7 
7 

7 
7 
7 

7 
8 
9 
13 
1  1 
ii 
9 

IO 

9 

8 

7 
7 
7 
7 
6 
8 
7 

7 
7 
6 

7 
8 

7 
8 
8 
8 
16 

16 

14 

IO 
IO 
IO 
IO 
10 
IO 

9 
9 

8 
7 
8 

7 
7 
7 
7 

2410000+ 
4336.58 

4344-54 
4345  •  54 

4353-54  { 

4354-54 
4362  .  54 

4365.54  { 
4372  •  54 
4377-54  | 

4386.54  -j 

4400.58 
4405  .  60 
4462  .  79 

4477-71  -j 

4503-7I 
4511-63 
4520.67 
4540.63 
4568.58 
4599-54 
46I3-54 
4624.52 

463i.54 
4634-50 
4650.58 
4654-54 

4661  .52 
4669  .  54 
4682.50 

4693-54 
4714.58 

4721-54 

4727-58 

4749-58 
4761.92 

4776.92 

4796.83 
4804.67 
4813-67 
4821.65 
4841.65 
4847.65 
4853-65 
4873-63 
4893  •  60 
4911.56 
4924-54 
4930.58 
4965  -  54 
4979-54 
4986.54 

4995  •  54 

150 
150 

150 
40 
80 
150 
40 
150 
150 
40 
150 
40 
150 
150 
150 
80 

275 

175 
275 
150 
150 
150 
200 
150 
200 
200 
200 
200 

200 
200 
150 

200 
150 
150 
150 

40 
40 
40 

40 

150 
150 
150 
150 
150 
150 
'So 
150 
150 
150 

200 
200 
150 
200 

6 
6 

6 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

12 

12 

8 

12 
12 
12 

6 
6 
6 
6 
6 
6 
6 
6 
6 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

6 

6 

6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 

21.6 
21.6 

25.0 

24-3 
25-6 
23-9 

25-5 
24.9 
24.4 

21.6 

20.9 
18.4 
ii.  5 
6.1. 

5-2 

3-7 
36 
1.6 
<  o 
<   i 
<  o 
<  o 

31 

2.  I 

10.07 
10.07 
9-50 
9.61 

9-43 
9.70 

9-43 
9-53 
9.60 

10.07 

10.  19 
10.61 
11.80 

12.79 

12-95 
13-14 
13-15 
13.60 

<'3-9 
<i3-7 
<i3-9 
<i3-9 
13-33 
I3-50 

good 

good 

fair 
good 

good 
good 
good 

fair 

fair 
fair 
good 

good 

moon 
good 
good 
good 
good 
good 
good 
good 
good 
good 

o 
8 
9 

17 
18 
26 

29 
36 

50 

64 
69 
126 

141 

167 
175 
184 
204 

295 
298 

+  0.32 
+  0.37 

—  0.2O 

—  O.  12 

-0.31 
-0.13 

—  0.46 

-0-45 
—  0.50 

—  O.2O 
-0.44 

—  o.  16 
—  0.62 

+0.08 

—  o.  16 
—  0.07 
—  o.  18 

+  0.10 

-0-34 
-0.15 

(1/26,  bic,  c6d,  d.5/,  J2e.  .  .  1 
\d2h  hig  g2k  g2/                j 

f  23.6,  25.2,  26.5.  .  ) 

1   2*1  2       24  Q  .  .         .  .  ( 

1/46,  v2l,  iii-2m,  0211,  nip.  . 

112-2,1,  mo-iv,  1/3-46  
ov,  V2p,  112-2,1,  D2-yi  

25.7,   24.5,    23.1.  ..(, 
27.2,    25.9,   25.7.  .  .) 
25.2,    26.5,    27.2,    23.6 
25.2,    22.6,   24.0  
26.2,  27.0,  26.2    .  .  .  ) 
23.6,   24.0,  26.2.  .  .  ) 
26.2,   25.0,  23.6  
23.2,   24.9,  27.0.  .  .  J 

25.5,  21.6  > 

22.  0,    21.2    ) 
22.O,  21.7,  21.  1    .  .  .) 
22.5,  2O-7,  19.6  
I7.I,    19.8    

13.6,  10.3,  10.8  

7-170                         .  .  ) 

V2l,  1/36,  mm  
oiv,  ii2m,  i/3/  
1/46,  mil/,  1/2,1  
i>3/,  vm,  v^b  
041;,  mp,  V2m  
i/o-  im,   ii2b  

TO3i/,  /i—  211,  1/1-26  

TO2-3D,  12-1,11,  lib  

62-31;,  T3-4C  
C3i/,  do-m,  i/3/  

f211,  €11,  HIS,  1/32  

5-8,  5-9,  7-0,  3-0.-) 

/6i/  g4i>  1/12,  limit  z   

3-9,  3-5  
3.9,  3.0,  4.1  
18   20    10  

11  not  seen,  limit  z  

11  not  seen,  limit  2  and  a.  . 
v  not  seen   limit  z  

v  glimpsed,  ma.  

39 
4-4 
5-5 
6.7 
12.4 
19.2 

22.  0 
27.6 
26.6 
26.5 

26.4 
19.2 

16.2 

15.4 
12.5 

8.8 

8.5 
6.8 

4-9 
3-4 
4-4 
<   4 

<     2 
<    2 

<   6 

<     2 

<  4 

13.16 

'3-19 

13.08 
12.90 
12.70 
ii  .67 
10.47 

IO.OO 

9.09 
9.26 

9.27 
9.29 

10.47 
10.97 

II.  12 
11.63 
12.31 

12-35 
12.68 
13-02 
13.28 
13.10 
<I3-2 

03  5 
<i3-5 

<I2.8 

<'3-5 

<I3-2 

good 

good 
good 
good 
good 
good 
fair 
fair 
good 
good 
fair 

fair 

good 
fair 
fair 
low 
good 
poor 
moon 
fair 
fair 
moon 
good 
good 
good 
good 
fine 
good 

325 
333 
346 
357 
378 
385 
391 
396 
3 
16 

30 

50 
58 
67 
75 
95 

IOI 

107 

127 
147 
165 

-0.25 

—  O.  IO 
—  O.O2 

+  0.15 
+  0.40 
+  0.67 
+  0.07 

—  o.  19 
-0.88 
-0.47 
—  0.46 

—  0.61 

+  0.18 
+  0.51 
+  0.41 
+  0.63 
+  0.64 
+  0.53 
+  0.71 
+  0.59 
+  0.46 
o.oo 

•j   e     A   A 

1/42,  em  
ii^a,  vo-ie,  g2ii  

bm,  me,  mo-  i2d  

i/3-4»i,  T/3-4/,  mo  
01-211,  112,1,  i>3m  

4-0,  4-9  
6.1,  6.4,  4.0  
8.9,  4.3,  7.0  
12.8,  ii.  8,  11.3,  14.0 
18.6,  17.3,  21.8  
21.  i,  23.0  
28.5,  26.7,  27.2  
25.7,  26.2,  28.0.  .  .  . 
25.8,  26.2,  28.0,  26.2 
(27.0,  25.2,  27.2.  .  ) 
j  25  9    26  8          .    ) 

112m,  1/2/,  110,  112p,    051;  .... 

/5i/,  m6v,  mb  
I6v,  63i/,  i/i—  2C  
631;,  co—  ID,  i/4(f  
C3—  41),  i/i—  2d  
dm,  vj,  114$  
d2—  311,  i/i/  

18.2,  19.0,  20.6.  .  .  . 
17.2,  16.6,  14.8.  .  .  . 
16.6,  15.8,  14.8  
12.8,    12.3  
9.8,  7.8,  9.9  
8.3,8.8  

v  glimpced,  ei—  211  

11  not  seen   limit  a  

v  not  seen   limit  a   .... 

v  not  seen,  limit  2  <ie  .  .  .  . 

CHAPTER   XIII. — Y   CASSIOPEIA. 


TABLE  114. — 8629  Y  CASSIOPEIA.     VISUAL  OBSERVATIONS  of  THE  VARIABLE. — Continued. 


No. 

Date. 

u 

• 

i 

1 

I 

< 

Comparison. 

Reduction,  Steps. 

Means. 

Seeing. 

t. 

A  Mag. 

Month 
and  Day. 

Hour 
C.  S.  T. 

Julian 
Day 
G.  M.'  T. 

Steps. 

Mag. 

54 

55 
56 
57 
58 
59 
60 
61 
62 

63 
64 

65 
66 

67 
68 
69 
70 

7i 

72 
73 

74 
75 
76 

77 

78 
79 

80 
81 
82 

83 
84 
85 

86 
87 
88 

89 

90 
9i 
92 
93 
94 
95 
96 
97 
98 

99 

IOO 
IOI 
IO2 
103 
104 
105 

1900 
Jan.     8 

24 
Feb.     9 
10 
19 
25 
Mar.   1  9 

21 

Apr.     4 
May      i 

20 
June  15 
July    12 
Aug.  14 
28 
Oct.    1  6 
25 
Nov.  26 
1901 
Feb.   10 
Dec.   21 
1902 
Aug.   15 
Oct.      i 
30 
Dec.   26 
1903 
Oct.    10 
Dec.     6 
1904 
Aug.     4 
29 
Sept.    2 
Oct.      6 
Nov.     3 
29 
1905 
Jan.      7 
28 

Feb.     9 
Mar.     3 

24 
May    22 
June     4 
26 
27 
July  30 
Aug.    6 

22 
28 

Sept.    2 
17 
19 

Oct.     20 
22 

3' 
Nov.  21 

»{ 

7 
ii 

7 
8 
8 
8 
8 
8 

'5 

H 
10 

15 
9 
9 
10 

7 

7 

7 
8 

9 
7 
10 

8 
6 

9 
8 

9 
9 

7 

9 

8 

8 

7 
8 
'4 
15 
12 

15 
12 

9 
I  I 

9 
ii 
8 
1  1 

8 

7 

12 

6 

2410000+ 
5028.67 
5028.68 
5028  .  68 

5044-54 
5060.71 
5061.54 
5070.56 
5076.56 
5098  .  56 
5100.58 
5II4-58 

5141-88  | 

5160.83 
5186.65 
5213-85 
5246.60 
5260.60 
5309  67 
53I8-54 
5350.54 

5426.54 
5740.58 

5977- 
6024.62 
6053.54 
6110.67 

6398.58 
6455  50 

6697-63 
6722.58 
6726.63 
6760.63 
6788 
6814.54 

6853-63 
6874.58 

6886.56  | 

6908.54  j 

6929.58 
6988  .  83 
7001.88 
7023.73 
7024.88 

7057  •  75 
7064.63 
7080  .  7  i 
7086.63 
7091.71 
7106.58 
7108.71 
7139-56 
7I4I-54 
7150.75 
7I7I-50 

350 

350 
350 
150 
275 
350 
150 
175 
150 
275 
275 
130 
275 
150 
'SO 
237 
150 
200 
460 

67 
40 

150 
350 

237 
67 
237 

67 
40 

150 
150 
67 
40 

40 

237 
237 
67 
275 
67 
275 
150 
250 
450 
300 
237 
237 
237 
237 
150 
237 
150 
237 
80 

237 
237 
ISO 

40 
40 
40 

6 

12 
40 

6 

12 

6 

12 
12 
12 
12 
6 
6 
40 

6 
6 

40 

12 

6 
6 

40 

24 
40 

12 

40 

12 

6 

6 
6 

12 

6 

24 

6 

40 
40 

12 
12 
12 
12 

6 
40 
40 

12 

40 
40 
40 
40 

6 
40 
6 
40 

12 

40 
40 

6 

v  not  seen,  limit  2</.  .  .) 
eis  double,  1  3  and  I3JM,5"  r 

<*  \—±Z.    2211  .  .                              .      } 

—  2.O 

14.18 

O3.6 
<I3  6 
I3-70 

<I2.8 

13-70 
13-55 
I3-40 
12.98 

11.23 

10.71 
11.03 
10.41 

12.22 
12.22 
12.68 
13.72 
<I2.8 

<I2.4 

12.47 

12.  0 

10-95 
11.26 
12.  06 

8-73 

11.22 

12.47 

12-55 
11.46 

10.86 

fair 

282 

+  0.45 

11  not  seen,  a  glimpsed.  .  .  . 

TI  not  seen,  limit  a  

moon 

3i5 

+  0.25 

SSv,  "2-31;,  112-32  
v  not  seen,  limit  e  

i.o,  -0.4,  2.5  

i  .0 
<6 
i  .0 
19 

2.7 
5-o 

14.8 
17.9 

15   0 

zm,  via,  limit  fl  

—  I  O    1  I 

good 

good 
good 

fair 

moon 
fair 

fair 
good 
good 
good 

330 

350 
354 
368 

396 

4 
30 
57 
90 
104 

153 
162 

+  0.50 

+  I.1O 

+  1.03 
+  1.23 

4-1.22 

+  0-99 
+  I.I3 
—  0.04 

+  0.53 
+  0.25 
—  0.28 
+  0.65 

Ti  glimpsed,  e\o  ±  

V2a,  V2Z,  g3i/,  e4V  
C3-4V,  -vig,  T>4-5a  

CI—2V,    Tl^d  

vS—  ioe,    /2—  36  

4.1,   2.0,  3.0,   1-9  

2.4,  7.0,  6.6  
»4-8,  14.8  I 

14..  Q  .                                 i 

62-3?,    V2-3C  

ayv,  TIC,  "vyi  
photometer  

17.1,  18.1  
15.0,  16.3,  13.8  

^2-36,  64-50,  d2V,  V2f  
d2V,    T12  j  

8.8,  9.8  
8.8,  9.8     

9-3 
9-3 
6.8 

i-5 
<6 

<8 
7.8 

J2V,     V2€  

S  8    7  q 

g4T,    VIZ  

2.O,   I.O  

v  not  held,  limit  g  

•v  not  seen,  limit  /  

vj  

good 

'74 

-0.74 

photograph  

641',  v  ic  
photometer  

15-6,  17.3  

16.4 

fair 
good 
fair 

good 
good 

fair 
good 
good 
fine 

48 
77 
134 

12 
69 

3" 
336 
340 

374 

4-0.74 
+  0.25 
-0.54 

-0.97 
+  0.49 

-0.83 
—  0.52 

-i-45 
-0.34 

photometer  

140,  17-86  
641),  C2v,  vqd  

dyv,  vie  

31.2,  27.1  
15.6,  14.3,  14.8  

7870 

29.8 
14.9 

7-8 
7-4 

fiv,  V2e  

6879 

photometer  

photometer  

photographs  

vl,  vm  
photometer  

23.2,  25.0  

24.1 

9.66 

IO.O2 
IO.2I 

II.  12 

"•73 

12.  2O 
13-0 
13-5 
I4.I 
I3-89 
I3-36 
I3-52 
13.28 

>3-7 
J3-07 

<I2.8 

12.31 

12.72 
13.01 
12.03 
ii.  Si 

good 

fair 
good 

fair 

fair 

low 
fair 
poor 
fair 
good 
good 
good 
good 
fair 
good 
dull 
good 
good 
poor 
good 
good 

18 

45 
78 

90 

112 

133 
192 

205 

227 
228 
261 
268 
284 
290 

295 
312 

343 
345 
354 
375 

—  0.06 

-0.48 
—  0.82 

-0.38 

-0.39 

-0.39 
-o.4± 
o.o± 
4-0.  4± 
+  0.23 
—  0.40 
—  0.24 

-0.44 
o.o 
—  0.60 

-i.  17 
-0.15 

+  O.22 

-0.37 
+  0.71 

photometer  

66i',  vie,  vsd  
651*,  civ,  v$d  
C4v,  vid  
c^v,  V2d  
div,  v/±  

13.6,  17.3,  15.8...  {. 

'4-6,  15-3.  15-8...) 
12.3,  ii.  8  ) 
11.3,  12.8  ) 
9.8,  7.8  

iS-4 

12.0 

8.8 
5 

2 
—  I 
O.  I 
30 
2.O 

3-4 
i 
4-5 
<6 
8.8 
6-4 
49 
10.3 
ii.  6 

jSv    v&a  

—  O  2     IO  I 

vn  i  

ayu  ±  

n2v  

fS—icrv,  via  
/8—  ion,  TJO.  

(-1.2),  3.1  

(-1.2),   21  

/6—  7^,  irja  

1-3,  4.  1  

z,  a  and  v  glimpsed  

J5~f>v,  1/4—50  

2.3,  6.6  

•v  not  seen,  limit  e  

vi  /.   /8<z±    . 

8  8    to 

JS»,   vie  
f  4—511,  i»6«  i    

3-8,6.9  
3.3,  8.1  

vrf,  div  

10.8,  9.8  

c$v,  vid,  i»3-4/  

11.3,  ii.  8,  11.3  

184 


RESEARCHES   IN   STELLAR  PHOTOMETRY. 


§ 


o 
<a 

S> 


=8 


m 
ot 

10 

-  o 
o 

03 


ki 


<o 

CO 


FIG.  38. — LIGHT-CURVB  OF  Y  CASSIOPEIA. 


CHAPTER   XIII. — Y   CASSIOPEIA. 


185 


TABLB  115. — 8629  Y  CASSIOPEIA.     MEAN  MAGNITUDES  PROM  34  j  DAY  GROUPS. 


Group  No  .  .  . 
I    D 

i 

2 

68 

3 

4 

1  17 

5 

171 

6 
20  s 

7 

21Q 

8 

271 

9 

708 

IO 
342 

ii 
376 

12 

f        t 

4.8 

60 

126 

I  ^4 

1  88 

2O6 

12  S 

•1C2 

^8O 

«36   \     £ 

I  No. 

r       t 

9.69 
—  0.06 

7 

16 

9  85 
—  0.40 

4 

eg 

10.61 
—  o.  16 
I 

II.80 
—  O.62 
I 

117 

12.87 
—0.04 

2 
156 

13-30 
—  0.05 
3 

13  4" 
—  0.24 

2 
282 

13.14 
—  0.  12 

3 

•^22 

12.80 
+  0.28 

2 

1S8 

10.31 
—  O.O9 

4 

-JQ6 

M 

TO  8^ 

12    85 

id   18 

1  1    7O 

T  -1       ^T 

4746    <      jig 

•  *7 

+  o  60 

+  o  23 

4-n   4S 

+  o  38 

+  1     12 

(.    No 

2 

2 

I 

2 

•7 

(I 

I  eg 

M 

10  87 

T  -1       2O 

JM 

_f_  j    06 

+  o  18 

No 

2 

(< 

'74 

M 

12    47 

M 

—  O    74 

Mo 

r       / 

48 

I  ^4 

M 

12    06 

5976         JM 

O    *\4 

i.   No 

r      < 

60 

12Q 

^74 

M 

8    71 

12.  l6 

10.86 

6386   1     JM 

—  I    O"? 

—  O    77 

L   No 

-I 

I 

ft 

18 

AJ 

M 

o  66 

10  66 

I  I    71 

JM 

—  O    1Q 

No 

1        * 
Means]    ^ 
I  No. 

16 
9.70 
—  0.06 

14 

53 
10-33 

—  O.02 
IO 

85 
ii  .46 

+  O.  12 
II 

121 
12.26 
—  0.05 

5 

m  159 

fi3  .00 

—  O.  II 

7 

1  88 
13-30 
-0.05 
3 

;::;| 
:::i 

291 
I3.67 
—  O.OI 

3 

325 
12.91 

-0.34 

8 

354 
12.90 
+  0.52 
6 

383 
10.50 
+0.17 

5 

TABLE  116.— 8629  Y  CASSIOPEIA.     OBSERVED  MAXIMA  AND  MINIMA. 
Elements  of  maximum.     1898  March  S  (J.  D.  2414354)+4IOd  E.     M-m=lS8'1. 


MAXIMA. 

MINIMA. 

H 

Date. 

Mag. 

Corr. 

Wt. 

•g 
o 
o. 
H 

Date. 

Mag. 

Corr. 

Wt. 

Calendar. 

J.  D. 

H. 

P. 

Calendar. 

J.  D- 

H. 

P. 

0 

i 

2 

3 

4 
5 
6 

1898  Mar.   ii 
1899  Apr.      8 
1  900  June     9 
1901  July   24 
1902  Sept.     7 
1903  Oct.    10 
1904  Nov.  27 

4360 

4753 
5180 

5590 
6000 
6398 
6812 

9.41 
9.  10 
10.57 

9.14 
8.83 
10.30 
me 
me 
8-43 
9-36 

+   6 
—  ii 
+  6 
+  6 
+   6 
-   6 

—    2 

7 
1  1 

7 
i 

2 
2 

9 

i 

2 

3 
4 
5 
6 

1  898  Nov.     4 
1899  Dec.    13 
1901  Feb.    16 
1902  Mar.   31 
1903  May    15 
1  904  June     8 

4598 
5012 

5432 
5840 
6250 
6640 

14.0 
14.2 

13-7 
13  9 
me 
me 
me 
me 

-  8 
—  4 
+  6 

+  2 

+  4 
-16 

17 
19 
4 
i 

2 

3 

8.70 
9-63 

1 86 


RESEARCHES   IN   STELLAR    PHOTOMETRY. 


DAYS 
100 SOP 3OO 400  SOO 


10 


Ul// 

5 

3 
H 

I 


8629  Y  CASSIOPEIAE 


Min,  =  i 
\         M-m  =  /58<t 


/3 


FIG.  39. — MEAN  LIGHT-CURVE  OF  Y  CASSIOPEIA. 


CHAPTER  XIV. 

GENERAL  CONCLUSIONS. 
I.  PRECISION  OF  THE    PHOTOMETER   MEASURES. 

The  tables  headed  "  Standard  Magnitude  Stars"  and  "  Mean  Magnitudes  of 
Comparison  Stars ' '  furnish  data  for  some  important  conclusions  in  regard  to  the 
precision  of  the  photometric  work.  The  method  of  reduction  of  the  measures 
with  the  6-inch,  as  explained  on  page  16,  gives  magnitude  values  for  each  of  the 
standard  stars  which  must  average  the  same  as  the  catalogue  values.  If  both 
were  perfect,  the  separate  residuals  between  the  catalogue  and  measured  magni- 
tudes would  be  zero.  Except  for  systematic  differences,  the  actual  residuals 
represent  the  combined  effect  of  the  accidental  errors  of  the  two  systems  com- 
pared. Table  117  collects  the  mean  values  of  these  residuals  for  the  three  standard 
stars  in  each  field  for  each  night,  expressed  in  hundredths  of  a  magnitude  and 
taken  without  regard  to  sign.  The  mean  residual  for  each  of  the  three  or  four 
nights  is  given  separately  from  the  Harvard  and  from  the  Potsdam  catalogue 
values.  Then  follow  two  columns  giving  the  means  of  all  the  nights  under  the 
headings  H  and  P  for  the  two  systems.  The  next  two  columns  give  the  number 
of  nights'  observations  and  the  mean  residuals  of  my  measures  among  them- 
selves. Then  follow  the  Potsdam  colors,  W  standing  for  white,  G  for  yellow, 
GW  for  yellowish  white,  WG  for  whitish  yellow,  the  plus  and  minus  signs  indicat- 
ing a  greater  or  less  degree  of  color. 

Before  these  results  are  discussed,  it  is  necessary  to  find  if  there  is  a  systematic 
difference,  due  to  color,  between  my  measures  and  the  two  catalogues.  The 
standard  stars  and  their  residuals  were  arranged  according  to  color,  and  means 
taken  of  five  groups  each  containing  at  least  four  stars,  28  stars  in  all.  It  was 
found  that  I  see  white  stars  fainter  and  yellow  stars  brighter  than  the  catalogues, 
the  range  between  white  and  whitish  yellow  stars  being  0.20  as  compared  with 
the  Harvard  and  0.07  as  compared  with  the  Potsdam  values.  Correcting  the 
28  stars  for  the  color  effect,  the  mean  residual  was  reduced  from  0.12  to  o.n  for 
the  Harvard  system,  but  remained  at  0.06  for  the  Potsdam  system,  an  effect  so 
slight  that  it  may  be  disregarded  in  the  discussion. 

The  results  of  Table  117  can  now  be  discussed. 

( i )  Considering  the  agreement  of  my  measures  among  themselves. — The  average 
difference  between  a  single  night's  magnitude  of  a  star  and  the  mean  of  the  three 
(or  in  one  case  four)  nights,  ranges  from  0.02  to  0.07  when  the  means  for  the 
three  stars  in  the  field  are  considered.  The  residuals  for  the  separate  stars 
range  from  o.oi  to  o.  1 1 ;  the  general  average  of  the  residuals  is  ±0.04,  correspond- 
ing to  a  probable  error  in  the  mean  of  a  little  less  than  0.03  magnitude.  The 
extreme  values  of  the  probable  error  are  ±0.0 1  and  ±0.05  for  the  separate  stars. 

187 


i88 


RESEARCHES   IN   STELLAR   PHOTOMETRY 


For  comparison,  in  the  three  parts  of  the  Potsdam  catalogue  the  probable  errors 
of  the  mean  of  two  nights  are  ±0.057,   ±0.040,  and   ±0.037. 

(2)  The  agreement  of  my  •measures  with  the  Potsdam  catalogue. — The  mean 
residuals  for  the  different  fields  range  from  0.03  to  o.n,  averaging  0.07  (the  maxi- 
mum residual  for  a  single  star  is  0.24).     This  is  just  about  the  residual  which  would 
be  expected  if  the  two  sets  of  measures  were  of  equal  precision,  as  the  residual 
0.07  is  the  combined  accidental  error  of  the  two  sets  of  measures. 

(3)  The  agreement  of  my  measures  with  the  Harvard  -values. — The  residuals 
range  from  0.05  to  0.28,  with  an  average  value  of  ±0.15.     If  a  color  correction 
were  applied  this  would  be  reduced  to  0.14,  but  would  still  be  double  the  residual 
from  the  Potsdam  catalogue.     It  is  realized  that  great  caution  should  be  used 
in  drawing  general  conclusions  from  the  measures  of  so  few  stars;  nevertheless, 
the  fact  that  the  residuals  from  the  Potsdam  system  are  persistently  (except 
for  S  Lyrae)  smaller  than  from  the   Harvard  system  seems  to  admit  of  but  one 
explanation,  the   greater   accuracy  of  the    Potsdam    measures,   and  the   close 
approach  to  the  Potsdam  accuracy  in  the  measures  of  the  present  series.     The 
basing  of  the  Harvard  measures  on  polar  stars  would  naturally  introduce  greater 
local  errors  than  would  be  the  case  in  the  Potsdam  measures,  which  are  based 
on  standards  near  the  measured  fields.     This  doubtless  accounts  for  part  of  the 
difference. 

TABLE  117. — STANDARD  MAGNITUDE  STARS.     AGREEMENT  OP  MAGNITUDE  RESULTS. 


Field. 

Residuals  between  ray  meas- 
ures and  the  catalogue 
magnitudes. 

My  measures 
inter  se. 

Potsdam  Colors. 

Harvard. 

Potsdam. 

Mean. 

No. 
nights 

Mean 
A. 

I 

a 

3 

4 

I 

a 

3 

4 

H. 

p. 

103      T  Andromedae.  .  . 
267      V  Andromedae.  .  . 
787     W  Andromedae.  .  . 
4315      R  Comas  

16 

9 
6 

14 
»3 

14 
4 

29 

12 

»7 
3* 
8 

«9 

'3 
a 
a 
7 

16 

8 
18 

16 
aa 

36 

'5 

19 
8 

17 
1  1 
II 
14 
3 

21 
19 

21 
32 

16 

20 

7 

2 

8 

10 

3 

i 

5 

18 

9 
7 

12 

6 

10 

4 

10 
12 

3 
5 
9 
6 

IS 

'3 
6 
6 

10 

2 

7 
a 
8 
3 
8 

10 

3 

ii 
ii 
6 

I 

18 

10 

8 
9 

10 

15 

5 

23 
13 
23 
a8 

13 

9 

3 
8 
8 
5 

3 
7 

1  1 

9 

10 
10 

6 
7 

3 
3 
3 
3 
3 
3 
3 
3 
3 
3 
4 
3 

3 

2 

6 
6 

4 
3 
3 
7 
5 
3 
4 
5 

GW-          W-        WG- 
W-          W-          W 
GW-      GW-        GW 
WG        GW              G- 
GW-      GW-        GW- 
W        WG          WG- 
GW         GW             W 
W-      GW-           W 
W        GW             W 
GW         WG          WG 
WG            G- 
G-      WG               G 

5798  RU  Herculis   .  .    .  . 

6100  RV  Herculis  

6894      S  Lyras  

7220      S  Cygni  

7269  SX  Cygni  
7458      V  Delphini. 

8518      Z  Cassiopeiae  .  .  . 
8629      Y  Cassiopeia?  .... 

Means  

*3 

4 

PRECISION  OF  MEASURES  WITH  THE  DIFFERENT  APERTURES. 

The  average  residual,  expressed  in  hundredths,  of  the  magnitudes  of  the 
measured  stars  (not  including  the  standards)  from  the  mean  of  all  the  nights, 
is  given  in  the  following  table  for  the  different  apertures  separately: 


CHAPTER  XIV. — GENERAL   CONCLUSIONS. 


189 


TABLE  118. —  MAGNITUDE  RESIDUALS  FOR  MEASURED  STARS. 


Aperture. 

6 

12 

40 

Mean. 

103      T    Andromedae.  .  . 

9 

9 

ii 

10 

267      V  Andromedae.  .  . 

8 

10 

7 

8 

787     W  Andromedae.  .  . 

7 

4 

6 

6 

43  15      R  Comse 

8 

6 

8 

5798  RU  Herculis  .    . 

8 

6100  RV  Herculis  

5 

6 

15 

9 

6894      S  Lyrae 

6 

7220       S  Cygni 

8 

18 

7269  SX  Cygni  

7 

g 

7458      V  Delphini 

7 

6 

8518       Z  Cassiopeia:  .  .  . 

8 

7 

5 

7 

8629     Y  Cassiopeia:  .  .  . 

6 

5 

14 

8 

7 

8 

II.  LIMIT  OF  VISION  OF  THE  6-,  12-,  AND  4O-INCH  TELESCOPES. 

An  interesting  result  of  the  present  investigation  is  the  photometric  magni- 
tude of  the  limit  of  vision  of  the  three  telescopes  used.  The  estimates  of  the  limit 
are  given  for  each  field  in  the  table  "Visual  Comparisons  of  the  Variable"  in 
steps  below  the  faintest  comparison  star  visible.  Table  119  collects  the  most  reli- 
able of  these  estimates,  made  in  good  seeing  and  classified  for  each  aperture  accord- 
ing to  the  ocular  used,  as  it  is  well  known  that  a  higher  magnifying  power  will 
show  fainter  stars.  Following  the  columns  giving  the  field,  date  of  observation, 
and  estimate  of  limit,  are  two  magnitude  columns  on  the  H.  C.  O.  system,  giving 
the  photometric  magnitude  of  the  star  used  in  the  estimate  and  the  resulting 
apparent  magnitude  of  the  limit,  using  as  the  value  of  one  step  0.14.  The  next 
two  columns  give  the  zenith  distance  and  the  reduction  to  the  zenith  resulting 
from  atmospheric  absorption.  The  final  two  columns  give  the  zenith  magnitude 
of  the  limit,  both  in  the  Harvard  and  Potsdam  systems.  Using  Pogson's  formula 

Limit  of  vision  —  9.0  +  5  log  aperture  in  inches 
we  have  the  following  comparison  between  calculated  and  observed  limits:* 


6-inch,  calculated 12 

6-inch,  observed,  ocular  1 50 12 

6-inch,  observed,  ocular  150 13 

1 2-inch,  calculated 14 

i2-inch,  observed,  ocular  275 14 

12-inch,  observed,  ocular  275 14 

4O-inch,  calculated 17 

4O-inch,  observed,  ocular  750 16 

4o-inch,  observed,  ocular  750 17 


89. 

90  Harvard  scale. 

02  Potsdam  scale. 

40. 

27  Harvard  scale. 

57  Potsdam  scale. 

01. 

8   Harvard  scale. 

i   Potsdam  scale. 


*  Compare  provisional  results  from  six  fields  in  Table  4,  page  10. 


RESEARCHES   IN   STELLAR  PHOTOMETRY. 


The  great  thickness  of  the  4O-inch  objective,  about  4^  inches,  requires  a 
correction  for  absorption.  Mr.  Lundin  informed  me  that  the  Clarks  estimated 
that  85  per  cent  of  the  light  was  transmitted  by  the  lens.  The  corresponding 
correction  is  o.  18  magnitude,  reducing  the  calculated  limit  to  16.83,  in  good 
agreement  with  the  observed  values. 

The  275  ocular  used  on  the  1 2-inch  was  made  by  Steinheil  and  is  of  good, 
but  not  unusual  transparency,  showing  a  limit  in  good  agreement  with  the 
calculated  value. 

The  6-inch  requires  special  mention,  since  it  is  a  silvered-glass  Newtonian 
reflector.  This  form  is  usually  credited  with  a  reflecting  power  very  much  lower 
than  these  measures  indicate.  For  example,  we  read  in  Young's  General  Astron- 
omy, paragraph  49:  "  In  a  Newtonian  reflector  in  average  condition,  the  percent- 
age (reflected  to  incident  light)  seldom  exceeds  50  per  cent,  and  more  frequently 
is  lower  than  higher."  If  this  were  correct  the  limit  should  be  12.3  magnitude, 
while  in  fact  the  reflector  does  nearly  all  that  could  be  expected  of  a  refractor  of 
equal  aperture,  in  spite  of  the  fact  that  the  mirror  was  silvered  only  three  times 
in  fourteen  years,  in  1892,  1897,  and  1903. 

It  should  be  noted  as  a  matter  of  greatest  importance  that  these  limits  of 
vision  furnish  a  check  on  the  adopted  absorption  curve  of  the  photometer  wedge 
used  in  the  work.  A  change  of  5  per  cent  in  the  curve  would  make  a  difference 
of  half  a  magnitude  in  the  range  between  the  standard  7th  magnitude  stars  and 
the  limit  of  the  4o-inch.  It  seems  justifiable  to  conclude,  therefore,  that  the 
absorption  curve  is  not  in  error  by  as  much  as  5  per  cent. 

TABLE  119-     LIMIT  OP  VISION. 


6-INCH,  OCULAR  40. 

Field. 

Date. 

Estimate 

Magnitude  H. 

Reduction. 

Corrected  Magnitude. 

Star. 

Limit. 

Z. 

Cor. 

H. 

P. 

T  Andromedae  .  .  . 
R  Comae       

y   m     d 
94  ii   20 

94     5  31 
04     5  10 
04  ii  30 
04  10    6 

2<X 

b 

z 
n 
ft 

13.  12 
12.29 
12.83 
11.84 
11.80 

13.40 
12.29 
12.83 
11.84 
11.80 

21° 

43 

34 
37 

22 

.01 
.08 
.04 
•05 
.01 

I3-4I 
13-37 
12.87 
11.89 
ii  .81 

13-49 
13-67 
13-17 
12.24 

12.22 

R  Comae           .... 

SX  Cygni  

W  Andromedae..  .  . 
Mean  

12.71 

12.96 

OCULAR  80. 

T  Andromedae  .  .  . 
V  Andromedae  .... 
RU  Herculis  
RV  Herculis    
RV  Herculis  

96  10  24 
98  10  ii 

97     7  23 
98     8  24 
98     8  22 

2-3  <k 

4<d 

P 
I 

11.85 
11.83 
13-42 
13.0 
13-0 

12.20 
12.35 
I3-42 
13-0 
13-0 

40 
46 

34 
26 
58 

.06 
.09 
.04 
.02 

.20 

12.26 
12.44 
13.46 
13.0 
13.2 

12.34 
12.73 

13-73 
I3-25 
13-45 

12.67 

13.10 

CHAPTER  XIV. — GENERAL  CONCLUSIONS. 


191 


TABLE  119.    LIMIT  OP  VISION. — Continued. 


6-INCH,  OCULAR  150. 

Field. 

Date. 

Estimate 

Magnitude  H. 

Reduction. 

Corrected  Magnitude. 

Star. 

Limit. 

Z. 

Cor. 

H. 

P. 

T  Andromedae  ..  .  . 
T  Andromedae  .... 
T  Andromedae  .... 
T  Andromedae  .... 
T  Andromedae  .... 
V  Andromedae  .  .  . 
V  Andromedae  .  .  . 
V  Andromedae  .  .  . 
V  Andromedae  .  .  . 
W  Andromedae..  .  . 
W  Andromedae...  . 
W  Andromedae...  . 
R  Comae  

y  m    d 
96     i   13 
97     9  20 
oo     i  24 
97     8  19 
oo     9  15 
97     9  20 
97  ii   16 
98     i   16 
98     i   18 
99     6  10 
99     7  29 
03  10  ii 
94     5  ii 
05     3  24 
05     3  24 
97     8  20 

97     9  14 
97   10  14 
97  10  23 
98     8  27 
98     8  27 
97     9  21 
97     9  25 
97  10  14 
98     4  26 
96  12  23 
97     9  22 
97  ii   16 
97  12  29 
94    6     6 
94    6  20 
94     7     2 
oo  10  26 
94    6  28 
94     8  26 
97     8  27 
99     7     8 
99     6  10 

OO      I       I 

98     9     7 
98  10     5 
98  ii     5 

3<k 

X 

4<k 
5<k 
4<n 
5<d 
g 

K? 
Kh 

2<h 
u 
Kb 
u 
z 
P 
P 
KP 
2-3  <n 
3-4  <™ 
2<n 

3-4  <•* 
4<* 
3<* 
3<* 

X 

2-3  <z 

z 
z 

X 
2<X 

2<X 

y 

i<a 

2<0 

3-4  <  a 
4-5  <a 
k 
Kk 
z 
z 
a 

11.85 
13.12 
13.12 
11-85 
11.85 
12.24 
11-83 
12-34 
12-34 
11.80 
11.80 
12.42 
12.29 

12.  8l 

12.83 
I3-42 
I3-42 
I3-42 
12-75 
12.40 

12.75 
12.67 
12.67 
12.67 
12.67 

12.  18 

12.82 
12.82 
12.82 

n-95 
H-95 
"•95 
12.31 
12.13 
12.13 
12.13 
12.13 
12-99 
12-99 
14.01 
14.01 
13-53 

12.27 
13.12 
13.12 
12-35 
12-55 
12.76 

12.53 
12-34 
12.48 
11.94 
12.08 
12.42 

12.43 
12.81 
12.83 
13-42 
13-42 
13-56 
13.10 
12.89 
12.93 
13.16 

13-19 
13.09 

13-09 

12.  18 

13.17 
12.82 
12.82 

11-95 
12.23 
12.23 
12.31 
12.27 
12.41 
12.62 
12.76 
12.99 

I3-I3 
14.01 
14.01 
13-53 

30° 
5i 
40 

63 
63 
56 

24 
24 
24 
61 
70 
52 
23 
46 
46 
34 
40 

55 
62 
40 
40 
26 
26 
36 
58 
65 

21 
41 

73 
48 
4' 
32 
16 
54 
34 
27 

49 
40 

18 
32 
32 
24 

•°3 
•»3 
.06 
.28 
.28 
.18 
.02 

.02 
.02 
•25 

•45 
•14 
.02 
.09 
.09 

•04 
.06 

•i? 
.26 
.06 
.06 
.02 
•05 
•05 

.20 
•32 
.OI 

.07 

•56 

.11 
.07 

•03 
.00 
.16 
.04 
.02 
.11 
.06 
.01 
•03 
•03 
.02 

12.30 

13-25 
13.18 
12.63 
12.83 
12.94 
12.55 
12.36 
12.50 

12.  19 

12-53 
12.56 

12-45 
12.90 
12.92 
I3-46 
I3.48 
13-73 
13-36 

12-95 
12.99 
13.21 
13-24 
13-14 
13.29 
12.50 
13.18 
12.89 
I3-38 
12.06 
12.30 
12.26 
12.31 
12-43 
12-45 
12.64 
12.89 
13  05 
13-14 
14.04 
14.04 
13-55 

12.38 

13-33 
13.26 
12.71 
12.91 

13-23 
12.84 
12.65 
12.79 
12.60 
12.94 
12.97 

12.75 
13.20 
13.22 
13-73 
13-75 
14.00 

13-63 
13.22 
13-26 
13-46 
13-49 
13-39 
13-54 
12.92 
13.60 

13-31 
13.80 
12.31 
12.55 
12.51 
12.56 
12.69 
12.71 
12.90 
I3-I3 
12-94 
13-03 
13-77 
13-77 
13.26 

R  Comae 

R  Comas 

RU  Herculis  
RU  Herculis  
RU  Herculis  . 

RU  Herculis  .    . 

RU  Herculis  

RU  Herculis 

RV  Herculis  .... 

RV  Herculis  

RV  Herculis  

RV  Herculis 

S  Lyrae     

S  Lyrae     

S  Lyrae 

S  Lyrac 

SCveni 

S  Cygni  

SCvsmi 

S  Cverni.. 

V  Delphini       .... 

V  Delphini  

V  Delphini 

V  Delphini 

Z  Cassiopeiae   .... 

Y  Cassiopeiae  .... 
Y  Cassiopeiae  

Y  Cassiopeiae  

Mean  

12.90 

13.02 

6-INCH,  OCULAR  20O. 

RV  Herculis    .... 
RV  Herculis 

99     i   10 
99     7     8 

OO       I    2O 

99     i     4 
99  10     2 

3-4  <s 
3-4  <•* 
40 

k 
Kk 

12.67 
12.67 
12.67 
12.99 
12.99 

13.16 
13.16 

I3-I9 
12.99 

13-13 

56 
16 
68 
32 
29 

.18 
.00 
•39 
•03 
•03 

13-34 
13.16 
I3-58 
13.02 
13.16 

13-59 
i3-4i 
13-83 
12.91 

13-05 

RV  Herculis  

Z  Cassiopeiae  

Z  Cassiopeiae  ..... 

Mean  

13  25 

J3-36 

192 


RESEARCHES   IN   STELLAR   PHOTOMETRY. 


TABI/B  119.     LIMIT  OF  VISION. — Continued. 


12-INCH,    OCULAR  67. 

Field. 

Date. 

Estimate 

Magnitude  H. 

Reduction. 

Corrected  Magnitude. 

Star. 

Limit. 

Z. 

Cor. 

H. 

P. 

RV  Herculis    

y    m     d 
04     8  ii 

4<a 

13-30 

13.86 

26° 

.02 

13.88 

I4-I3 

OCULAR  80. 

W  Andromedse..  .  . 
Z  Cassiopeiae    .... 

03  10  13 

00      2    25 
00       2    25 

2 
4<fc 

1<X 

13-34 
12.99 

13-38 

13-34 
13-55 
I3-52 

70 
48 
48 

•45 
.  ii 
.  ii 

13-79 
13.66 

i3-63 

14.20 
13-55 
«3-52 

Z  Cassiopeiae  

Mean  

13  69 

13-74 

OCULAR  275. 

V  Andromedae  .  .  . 
R  Comas  

98     7  25 
oo     4     4 
oo     4     4 
oo     3     7 
oo     4     4 
oo     4     4 
oo     4     4 
oo     4     4 
oo     4     4 

OI    II       I 
OI     II       I 

C 
Y 
i</J 

•w' 
•w' 

,3 
V 
8-10  <z 

a 

3<y 

at 

13.82 
14.17 
14.08 
14.68 
14.68 

14-75 
14.26 
12.82 
14.01 
13-50 
13-73 

13.82 
14.17 
14.22 
14.68 
14.68 

J4-75 
14.26 
14.  10 
14.01 
13.92 
13-73 

46 
34 
34 
40 

22 
2O 
2O 
4' 
41 
51 
51 

.09 
.04 
.04 
.06 
.01 
.01 
.01 
.07 
.07 
•"3 
•'3 

I3-9I 
14.26 
14.  26 

14-74 
14.69 
14.76 
14.27 
14.17 
14.08 
14-05 
13-86 

14.20 
14.56 
H-56 
15.01 
14.96 
15.01 
14-52 
H-59 
14.50 

I4-31 

14.  12 

R  Comae 

RU  Herculis  
RU  Herculi';  

RV  Herculis    
RV  Herculis 

S  Lyrae     

S  Lyra   

V  Delphini 

V  Delphini       .    . 

14.27 

14-57 

40-INCH,  OCULAR  237. 

V  Delphini  

02     4   12 
02     4  12 

4<A 
2-3  <7T 

16.2 
15-2 

16.7 
15.6 

62 
62 

.06 
.06 

16.8 
15-6 

17.2 
15-8 

V  Delphini 

Mean          .  .  . 

16.2 

I6.5 

OCULAR  350. 

RV  Herculis    

02       2       5 

6<k 

15-50 

16.25 

51 

•13 

16.38 

16.63 

OCULAR  450. 

V  Delphini 

oo  10  16 
05  ii   18 

!«</£ 

5-6  <t 

15-3 

15-48 

16.1 
16.25 

34 
16 

.04 
.00 

16.3 
16.25 

16.6 
16.50 

S  Cveni    . 

OCULAR  750. 

V  Delpbini 

oo     8  29 

i«<M 

16.2 

. 

16.7 

Si 

13 

16.8 

17.1 

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